Help!!!!

We weren't friends but I did this girl's hair about 3 times and then over the summer my boyfriend cheated on me with her. I broke up with him and I forgave her even though she never apologized and I never showed her any hatred. It's about 2 months since I found out and last night she texted me asking if I can do her hair.

Part of me wants to do it because I forgave her and I don't think I should hold a grudge against her. But the other part of me is upset because she has the audacity to ask me to do her hair again after she did the 69 position with my man knowing that we were still together. And she never even apologized for it or acknowledged that she was wrong for it.

So what should i do guys????