I don't recommend this course of action simply because it has too many chances of backfiring. What happens if she takes you at your word, assumes you're both moving on? You're left feeling as you do with no room to communicate anything without having to admit you intentionally played a mind game. Not a good look.
I know you're hurting. I can't imagine that level of hurt.
She's made it clear that she wants to move on, which leaves you with 2 choices. Pine over her forever, being a sad example for your child OR learn to get over her and move on also. I'm not saying either choice is easy, but one is certainly less painful in the long term and I'm sure you know which one I mean.
'People are never perfect but love can be. People waste time looking for the perfect lover rather than creating the perfect love' - Princess Leigh-Cheri from Still Life With Woodpecker.