Spokesman Simon Clare said Thursday that the company had taken 10,000 bets on various names but he was surprised to see about $3,080 in bets on Alexandra in a matter of hours.
Rivals William Hill and Ladbrokes also have Alexandra as the 2-1 favorite.
Earlier, Coral had suspended bets on the baby being a girl. At an outing last month, the former Kate Middleton appeared to let it slip that the baby would be a girl.
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