I really hope they don't use any newfound celebrity "friends". They have plenty of family and old friends on Harry's side from which to choose.
Say what you will about Meghan, but I don't think it would be fair to choose all of them from Harry's side - she deserves to include her friends as well.
My first thought had been Jessica Mulroney - but perhaps they're not as close as they used to be?
Not sure about Serena - are they still close? She made a major error with the baby and referred to the baby as female before he arrived, so perhaps she doesn't have the information we assumed she did, or perhaps it was just a slip of the tongue.