People change....sometimes daily. Whether or not she was cruel to you, your whole life, she is still your mother. Her being cruel to you was just a reflection of how she was feeling, which was more than likely ba<x>sed on fear. It is not worth holding a grudge or refusing to forgive her. I think she wants you to tell her that you forgive her, and it is probably the best thing for you as well. When we let things like that linger, we never truly afford ourselves the opportunity to get over it, and it continues to negatively impact us. If you want to feel good about your whole experience and relationship with your mother, forgive her. You'll feel better instantly.
block her number
Maybe she feels like she needs your forgiveness or approval in order to have inner peace. I say don't give it to her. Now the shoe is on the other foot - you're in a position to make her suffer.
Perhaps she has mellowed with age. Similarly, she might have suffered from mental problems but now has a better handle on them. Just guesses.
Maybe she's come to regret what she did. People change, just takes longer for some.
That's a very difficult situation. I've never been in it personally, so I can only use any knowledge and wisdom I've gained through my own experiences to answer. I find that sometimes people change, better or worse, and that you have to each side of them into separate compartments. You'll have to decide if you can let go of your anger - righteous as it may be - and take the chance at having the mother you never got to have, if she's genuinely changed.
If she is still that way, then she's obviously not someone you would want to be around.
You can't expect to know what's in the head of a woman I've never met all I can do is guess