Looks like it might be a spur, but the pic is too blurry to tell for sure. One of my girls has a spur on one side that's much longer than the other one and it looks similar to that.
If your snake has RI the sooner you get to a vet/find some way to treat it the better her chances of surviving. If you have her near the other snakes they're all at risk no matter what you do. Waiting will only make everything worse.