Forgiving a betrayal

So I was massively betrayed by my mom two years ago. Until then we always had a super close relationship. We spent a year going to different counselors in which she fudged the truth and put on a fake persona. Before this my mom was my role model, so having her turn on me then lie on me was traumatic. I felt like it was the twilight zone.

We made up but she never acknowledged what she did to me, which has caused me to be polite but distant. I felt like the mother I knew was dead, so it was hard to just have the same quality relationship we used to enjoy.

Fast forward two years, and I am as polite and distant as ever, and Mom is very lonely. She doesn't have me like she used to, so she's very isolated now.

Yesterday my sister told me Mom was crying because she felt alone, so today I called her and asked if she wanted to hang out, and she was so eager and grateful sounding. I know she misses me.

Trouble is, what she did always flutters in the back of my head and I don't know if I should stay aloof to keep from fighting with her or just accept that she'll never apologize and put myself out for her like I used to. Talking to her about it is not an option. She changes facts, lies, and denies everything and gets really worked up.

What should I do?