Is it okay that I sometimes miss my abuser?
Do you want to get back in touch with them?
No, this has nothing to do with meeting again, it's just me missing her.
While you have the right to miss them as they were still your girlfriend, it's unhealthy to constantly think of them. They are an abuser, and they don't deserve your time of day and it's good you managed to get out. You need to seek therapy to finally let go of them.
But she means a lot to me
I understand that you felt for her, and it can be psychologically normal to miss someone who abused you, but you need to realize that it was no good for you. You deserve better than being abused and it is good that you got away from her, and while sometimes you might miss her, you should stay as far away as you can.