How do I keep my grandma from commenting on everything on my Facebook?

[FSBB]

I love my Grandma. She's awesome. My aunt made her a Facebook kinda as a joke so she could see social media and be friends with the family. She has like 10 friends, so she does it so she can see what we're up to at college and stuff.

Thing is, she comments on EVERYTHING. Literally, every single post I make. Even when someone tags me in a picture, she comments. They have no idea who she is so it's kinda awkward.

This is why I try to stay away from family on Facebook. It's not because I have inappropriate content. It's just I feel Facebook is more a friend thing.

Anyway, I know how to hide status updates......that's under control But is it possible for me to just make it so she can't comment on certain things? This applies to other family members as well. I don't want to block everything from them, just certain aspects.
I want her to be able to see some things. I know how to hide my own status updates, but commenting on pictures and stuff is what I want to block her from.