Is it really that bad to hold a genuine grudge against someone?

I had to cut my hair off years ago because a girl I knew maliciously poured gorilla glue in it. I have never been able to grow it back out since. My hair regularly falls out now, so I don't think I'll ever have another chance to grow it to the same length again. She came back after all this time and tried apologizing and said that I look nice and all that. I don't believe she's being genuine for a second. I look awful. I don't know what she wants from me, but I know that I want nothing to do with it. My friends say I should try talking to her because she seems interested in me, but I don't know. I think she's plotting something
Is it really that bad to hold a genuine grudge against someone?
Post Opinion