Best thing to do is keep your snake warm (normal heat gradients in the enclosure, nothing extra crazy) and don't pick it up; handling it will increase the likelihood that it will regurgitate.
Snakes can take down food a lot bigger than most people give them credit for. If it really is too big she will regurgitate it and should be no worse for it. If it was small enough for her to swallow its small enough to come back up if her system can't handle it. Don't fret too much.