Here are some ideas for online games/videos/info that might keep her busy for a while. Doing the EPGY open enrollment or another program of that sort sounds like a great idea as well.
Maybe you can make social skills into part of your curriculum. It is understandable that a 3-4 y/o wouldn't have mastered that yet and given how out of step she is with her age peers also understandable that she is frustrated. Like others have said, it will benefit her to have that be something she spends time working on, though.
