I have a character who's a mom that was raised in an abusive household so she's almost compulsively loving towards her own daughter, but will sometimes playfully give her a noogie. While writing the scene I was thinking is giving a kid a noogie a normal thing a mom would do, but it just felt right for this character. (The context was the daughter was helping her rehearse a play-she's an actress-and the scene required the mother to slap her, but she couldn't do it even as a part of a play so she gave her a noogie instead.)
I don't think you can go wrong here. The question isn't whether 'a' mom would do it, but whether 'this' mom would do it, and you've already answered that. I'd leave it as-is.
I can identify with your character. You are right, a person who was abused by a parent might have made a vow never to hit her children. She would not want to do it even as "pretend."