Social skills were very big issues for me (for different reasons - primarily the late diagnosis of my disability - all my IEPs that I found had a big emphasis on social skills). As a adult, I still find it hard to deal with large social settings especially if it involves a noisy environment.

Unfortunately for elementary school, I have no suggestions since those years for me were the years I struggled the most with social situations and making friends that I trusted - but one place where I found refuge in the latter part of my elementary school years was the barn - mostly because with horses and dogs, I never had to struggle with trying to figure out social nuances that came naturally to everyone else since animals don't care about that, and because the topic of horses would allow me to interact more naturally with others who had the same interests and not be constantly on guard or trying to decipher their body language, words etc. (as an adult, I have found similar refuge in a different sports environment - for similar reasons)

Is there something like that - an activity that she enjoys that she could spend time with others who have the same interest - that is away from those mean kids? That may allow her a place to just be herself, and then all the emphasis on social skill learning won't be so overwhelming.