African parents struggle with seeing their kids as adults so don't take it to heart. Set your boundaries and just keep a little distance. Who knows maybe when you have kids, it might help her start to mellow out a little bit
This is the part we all gotta reject though. Parents shouldn't have to become GRANDparents in order to calm the fukk down. I know they mostly mean well, but people (parents included) need to understand that if they want to have relationships with folks they have to understand boundaries.
I've had this issue with my mother before. I'm her only kid so we talk a lot, mostly about innocuous things. But what she failed to realize is that when I got married, she had to take a back seat. My wife is the priority now.
But beyond that, its hard for mothers especially to see their kids as adults especially black women. Mostly because the good ones put SO MUCH into their children. So to let that go is like letting go a part of yourself. Literally. But sometimes people gotta rip the Band-Aid off.