forgive and forget or just forget?

This past fall a couple people I was on good terms with and one or two I thought were good studied abroad. Sadly what was touted as a very good bonding experience led to the whole group being split into 3 camps. Mainly 2 girls, a couple, and myself were the core of these camps. I was more or less by myself by the end of it and just cut myself off from everyone else. I made amends with the couple since we didn't really have any issues to begin with, but everyone else has issues with me.

The general animosity I've been able to put together is that the reason why they no longer talked to me and lied to my face and ditched me about extra curricular travel plans was that I was not being a good project partner to another girl that:
Everyone secretly hated
Made me do all the work, then claim that I was the lazy one when I couldn't defend myself because I was dealing with depression and added trauma from sexual assault. (And I explained this to them.)

So, because of me being a partner to someone that they didn't even like, they ditched me on something we were all planning on doing since before we even got there. That naturally ticked me off, and was the initial reason why I didn't want to talk to them.

since then, I've dropped the issue, I'm no longer upset about what happened, and have nothing against them as people. That being said, I feel like I can no longer become friends with them because of what happened, they dropped me when I needed help, and lied straight to my face. I just don't feel like I can trust them.

Now that everyone was back home, any issues one of the girls had with the couple should have dissipated, but they didn't and she started to cause a lot of trouble for them, so far as interfering with their work. This caused the couple to tell the department of our school and the girl then threatened to go to the police since the couple smoked pot in order to get them to shut up. Needless to say I have no wish of reconnecting with her. I'll be civil and be myself, but she has a almost no chance of being a friend.

now the other girl is what the thread is about. Due to a series of unfortunate events we talked for the first time yesterday, 3 months since the fiasco. In order to contact me though she needed to go through my best friend to reach me, and expressed to my friend that she feels bad about what happened and that she wants to be friends again.

Immediately without thinking I just want to say no, but after thinking about it I feel that I should talk to her to see if she will talk to me directly, and have everything out in the open. If we can move on I will have to keep her at arms length until I can trust her again. Does that sound fair? Any other ways people would treat something like this?

 

Hey, so we talked for the first time briefly on Wednesday and I don't want to leave too much time before talking to her again, I could use guidance or reassurance that what I'm doing makes sense.