Meghan Markle and Prince Harry Meghan Markle and Prince Harry
Many believe that Harry will pay tribute to his late mother, Princess Diana, by naming the baby after her, whether it's a boy or girl. Betfair has the name Diana has its frontrunner with 10/1 odds while Spencer is a possibility for a little boy at 25/1.
Ladbrokes also has Diana and Spencer as popular picks, with 6/1 and 10/1 odds, respectively.
"Royal punters are seemingly convinced Harry and Meghan's second born will be named after his mother, regardless of whether it's a boy or a girl, as Diana and Spencer are currently proving the most popular picks in the betting," Alex Apati of Ladbrokes said.
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Misan Harriman Prince Harry and Meghan Markle
Alfie and Alexandra top the leaderboard at Ladbrokes with 4/1 odds, while Betfair places Arthur (10/1), Thomas (12/1) and Isabella (12/1) with the highest odds.
However, less traditional monikers for the royals are also in running. Ladbrokes has Doria, after Meghan's mother, in consideration with 12/1 odds, along with Emily (10/1), Sebastian (12/1), Marina (12/1) and Willow (14/1).
Betfair spokesperson Sam Rosbottom said, "Having picked Archie — a name that wasn't even on our list, for their first child — the odds suggest Meghan & Prince Harry could opt for a more traditional name for their second with Arthur and Diana the joint 8/1 favorites with Betfair."
Henk Kruger/AP/Shutterstock Meghan Markle, Prince Harry and Archie
The Duke and Duchess of Sussex announced that they are expecting their second child together on Sunday. The baby will be the younger sibling to the couple's son Archie Harrison, who will turn 2 on May 6.
"We can confirm that Archie is going to be a big brother. The Duke and Duchess of Sussex are overjoyed to be expecting their second child," a spokesperson for the couple told PEOPLE.
Meghan, 39, and Harry, 36, announced their pregnancy news with a stunning black-and-white photo that was taken remotely via iPad by their friend and longtime photographer, Misan Harriman. A smiling (and barefoot!) Harry looks lovingly at Meghan, who cradles her baby bump as she rests in his lap.
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The happy news — which they shared on Valentine's Day — comes after Meghan revealed she suffered a miscarriage last July. "Losing a child means carrying an almost unbearable grief, experienced by many but talked about by few," she wrote in a New York Times essay on November 25.