Jesika,
Sorry to hear of your troubles. I can imagine how upset you must be. Here's my advice for all its worth.
I wouldn't fight it. Here's why. When I was a kid I never had a relationship with my grandparents. My mother didn't get a long with them. As an adult I looked them up and reestablished a relationship with my grandmother. Unfortunately she died shortly afterwards and my grandfather had died before I made contact. I felt like I missed out on knowing and being loved by a grandparent.
Oddlly eneough that I give you this advice when I , myself have nothing to do with my own mother. Therefore, my 2 daughters do not have a relationship with their grandmother. The few times she has called or has sent presents or letters , I always allow that communication. My mom plays head games , lies, makes herself out to be the victim ect. ect. ect. It sounds similar to your situation. My mother is probably worse. She's downright mean to me and tries to make my kids feel sorry for her. This is how I handle it and so far its worked well. I never call her or write her or go see her. Its been a year. When she sends a letter to my kids I give it to them but don't read it myself. Why upset myself further. If she calls I'm polite but make it as brief as possible and hand the phone to my daughters so they can chat. If she wants to see the kids , fine. I just don't go over. My husband will do it for me.
I tell my daughters the truth about why I don't talk to their Grandmother. I don't think she's healthy for them to be around but for some reason they like her. Its beyond me!!! I've come to the conclusion that its between me and my mom and the kids should be left out of it.
Jes, If she does fight this and gets visitation it may not be as bad as you think. Your the Mom. You have the most influence on your childs life.
Take care
jurs