The 35-year-old TV presenter hinted that the dad-of-two, 36, is broody for a third child.
In an interview with The Times, Christine said of the Manchester City star: "He'd have one in the morning. He's a proper little daddy."
However, right now, first-time motherhood for Christine is going to have to wait because the couple are too busy.
Christine has joined Philip Schofield on the This Morning sofa during Holly Willoughby's maternity leave and she also presents a Sunday afternoon radio show on Magic FM.
Meanwhile, Frank is waiting to go to the States to play for New York City FC.
He said he's 'very firm' when it comes to bringing up his daughters Luna, nine, and seven-year-old Isla, his daughters with former fiancée and model, Elen Rives.
He said: "I am very firm to be honest. I hate the idea of spoiling them. I hate the idea of spoilt kids. It's quite lazy in a way for parents to just buy toys.
"My kids only expect what they're given. If you give them a baby Ferrari what do they want next year?"
However, he hopes their regular visits will make them more worldy-wise.
He added: "I'm fortunate enough with the girls that they are going to come out and have their holidays there. I hope it will be a life experience for them too. I will make it work.... I will miss them a lot. I want to make sure that when I come back nothing has changed.
"I'll do whatever it takes to make that happen. But it's my job - I have to do it and I want to do it."
The idea of his kids remaining grounded is especially important to the top earning sports star, who has written a series of children's books, Frankie's Magic Football, which deal with the ideas of greed.