EVERETT — Micaela Powell walked from her Madison neighborhood home to nearby stores last week, an 18-year-old in search of a summer job.

It took her more than an hour to walk the one-and-a-half-mile loop. Even at this distance, it was a milestone, the longest walk of her life.

Powell, an Everett High School senior, was born with multiple heart problems. They included a hole in her heart and a heart valve that helped regulate blood to her lungs that didn’t close properly. “She turned blue really easily,” said her mom, Jennifer Powell. “Her heart didn’t have enough ‘pump’ to it.”

Micaela Powell had her first heart surgery in 2003, when she was 7. Two more surgeries followed in 2007 and 2012.

“The surgeries would give her a little bump in energy,” her mom said. “She got better for a while, then she would progressively decline. Her heart was oversized, overworked and slowly wearing out.”

Her third surgery, when she was a high school junior, caused her to miss two months of school.

Doctors at Seattle Children’s Hospital first broached the subject of a heart transplant about five years ago. “It took her a while to come around, to be convinced that she needed one,” said Dr. Erin Albers, a transplant cardiologist at Children’s. “She was nervous about another operation and all the things that come with a transplant.”

Powell’s heart problems had slowly pruned away many common activities from her young life. “She hasn’t taken P.E. since third grade,” her mom said. “She couldn’t do sports. There’s a lot that spilled over into our regular life. ‘No, we can’t go on a family bike ride. No, we can’t go hiking.’ ”

By the time she was a senior, Powell had to stop to catch her breath as she walked up a flight of stairs. “It’s tough when you go to a three-story school,” she said.

Everett High School’s campus, with seven buildings, is spread across three city blocks. Traversing it left her unusually fatigued. “I was worried about just walking across campus,” she said. “I’d walk two blocks and get shortness of breath. I couldn’t walk that far.”

On Saturday, Powell will take another walk, this one to pick up her high school diploma. Dressed in a navy-blue graduation cap and gown — four months after getting a new, transplanted heart — it will mark more than the usual rite of passage.

After years of her life becoming ever more restricted, Powell is now coming to terms with an expanding horizon of expectations and opportunities.

It begins this summer, with activities that for years she’s had to watch others enjoy. “I’ve always wanted to swim, to get on the swim team in high school, and basketball was also in the back of my mind,” she said. “Skateboarding. I’d have to learn to balance first. I’ll be able to do anything I want.”

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Powell’s name was added to the list of people waiting for a donated heart on Jan. 6. “Her life was kind of on hold,” her mom said. “We weren’t registering her for college or encouraging her to get a job. We told her not to make any summer plans.”

The wait for a new heart at Children’s is typically about four months, but Powell and her mom braced themselves for a wait that could have stretched to six months or a year.

Powell’s sociology teacher, Don Wilson, thought it would be good to have a just-in-case plan. He outlined an independent study that would allow her to keep on track academically.

“We kept it in our back pocket, making a transition out, a transition back in,” Wilson said. “The trigger got pulled a little quicker than we thought.”

On Feb. 14, about 10 p.m., Powell’s family got the call. She had been matched with a new heart. “She just happened to be the right size and blood type at the right time,” Albers said.

The surgery, which began at 3:15 p.m. on Feb. 15, ended at 10:40 that evening. It can be a long operation, especially for patients who have had surgeries before, due to scar tissue and adhesions. Powell’s surgery was one of about 16 heart transplants conducted at Children’s each year.

Powell recovered quickly from the surgery, although not without pain or sleepless nights. Just nine days after her operation, pictures show her smiling in her hospital bed, surrounded by family and friends.

It wasn’t long before Wilson began getting emails from his student, asking for homework. “She got a ton of it done, apparently while she was still hooked up to machines,” he said.

She left the hospital on March 1, a little more than two weeks after her surgery. Her belongings included a plastic bag filled 15 medications, including anti-rejection pills.

“She was on complete quarantine for three months,” her mom said. “After the transplant, they have to pump your body full of immune suppression drugs. They didn’t want her going to school, church, the grocery store or the movie theater where she could catch any kind of germ.” She watched as her daughter went “a little stir crazy.”

Powell’s mom was able to spend those three months at home with her daughter for reasons she never anticipated. Just two weeks after her daughter was put on the transplant list in January, Jennifer Powell was laid off from her engineering job of 17 years. She spent the time they were together trying to keep her daughter entertained while vigilantly monitoring her blood pressure, pulse and temperature.

As Powell continued working on classwork at home, Wilson, her teacher, was getting emails from her with increasing frequency. “She’s got a level of commitment that you can’t put a number on,” he said. “She clearly knows what she wants, and the most important thing is, she’s willing to do with it takes to get there.”

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Powell returned to classes on May 5, two weeks earlier than scheduled. “She was begging to go back to her senior year,” said Albers, the Children’s Hospital physician.

No one but her school counselor, Kendall Berry, knew Powell would be walking into her high school that Monday. Her surprise re-entry made for emotional reunions.

“I made a lot of people cry; I cried, although I kinda had mixed feelings,” Powell said. She had spent months anticipating her return to school but kept thinking of the warnings to be cautious of germs. “I couldn’t hug my friends, but it was still an exciting day,” she said.

Her goal was to graduate on time. She was making up work from three months of missed classes. “There’s kids who ask, ‘Can you cut me some slack because I went to a game last night?’ ” Wilson said. “She’s never asked for any kind of exception. It’s always been, ‘Give me more.’ ”

As year-end finals approached, Wilson said that Powell was earning B’s or B-pluses. “Sometimes I had to tell her, ‘Let this go. Just do the main ideas. Pace yourself. You’ve got other classes.”

In the school’s band room, Powell, a flutist, was back at her regular front row seat. During the band’s year-end concert at the Everett Civic Auditorium on Thursday night, her classmates surprised her with an award: She was one of two people voted Most Inspirational.

Signs of the end of the school year and the end of high school seemed to come in bunches. She picked up her graduation cap and gown last week on the same day that she and her mom picked up her pink dress for Saturday night’s prom.

“She’s transitioning from being a kid to an adult and from being sick to being healthy — doing both of those at the same time,” her mom said.

After the walk through her neighborhood in search of potential summer jobs last week, Powell told her mom that she was a little out of breath on the hills, but her heart seemed to keep up just fine. “She hasn’t worked out in 18 years,” her mom said. “It’s a matter of getting her body in condition.”

Powell feels a mix of both anticipation and bittersweet emotion for her upcoming life changes. She’s been accepted at Everett Community College, where she plans to enroll in the fall.

“I’m ready to move on and do bigger and better things,” she said. “Eventually, I’ll move out and do things on my own. It scares me a little bit.”

So much has happened over the past six months — turning 18 in January, having a heart transplant a month later and cramming to finish her classwork — that there has been little time to reflect on what she’s accomplished.

For now, she’s focused on getting a summer job. Her walk to check in with potential employers was memorable not just for the milestone of its length, but also as a symbol of her passage to adulthood.

“I was seeing if anyone was hiring,” Powell said. “It turns out three places are, near my house. If I had to walk, I could.”

She included one potential job site in her walk that was down the hill from her house. “I made it my goal to walk there,” she said. “I stopped at multiple places. Three places were hiring. I’ll apply to all three.”

Sharon Salyer: 425-339-3486 or salyer@heraldnet.com.

Stories on the Class of 2014

• Justin Cho, Jackson: A slow, grueling comeback from sudden illness

• Jasmin Edwards, Lynnwood: She excelled in the classroom and on the court

• Micaela Powell, Everett: After transplant, she has a new heart and new horizons

• Josh and Zach Rodriguez, Arlington: Twins will head down separate paths

• Josh Sharpe, Snohomish: Under the burden of loss, he carried on

• Santana Shopbell, Tulalip Heritage: She set a goal — and an example for others

• Michael Wanner, Kamiak: At West Point, he’ll learn to be a leader