Is there no way for Val to beat Abigail or do I just suck?
Use possession to recover Val's hp and get early on enemies before using other powers to help Val avoid damage. You can also possess other enemies to hit each other. If there's too many enemies or you need a chance to recover, push Val into an object to hide her. Remember that hp recovery applies to all adjacent characters, so you can't make much progress while healing enemies. Abigail does 2 damage a hit, while every other character does 1 right now.