Thank you for your replies everyone.

A few things. I was feeling depressed lasts night and very isolated. In a bit of emotional impulsivity, I ended up un-tagging myself in 2 old pictures she'd tagged me in, that I'd never really wanted on my page. I hope she does not find out or notice. But yeah. I am sort of scared of her. Which bothers me.

So she is at it again on facebook trying to gain sympathy from people (and succeeding) about her mother not wanting anything to do with her. Ugh.

I did speak to my cousin. She was very nice about it and told me her own thoughts on this woman (she dislikes her and cannot stand what she did to her children). She actually unfriended this woman a while ago because she did not want to be a part of her drama. It was very validating to hear this from her AND I ended up feeling close to and bonding a little with my cousin. She gave me some advice: keep my distance. She knows its harder for me, because I live closer to her (my cousin lives in a different state). But yeah. I really appreciated hearing that.

I think I just need to live my life and not worry about this woman. I think unfriending her or blocking her will cause major problems for me. She'll go after me. It will be awkward at family gatherings, etc.