If she is showing obvious signs of distress(writhing and flipping over onto her back, for instance) and you can euthanize in a method that will not cause more distress, then it might be best.

It's difficult to help make the decision when we aren't watching the snake. if the door closed on her hard enough, she may have broken bones. Snakes have a lot of flexibility, so maybe she's just badly bruised up. That would probably take an Xray to determine, but then, most vets probably can't do surgery to pin bones as tiny as a snake's facial bones would be.. so again, it's going to be a difficult decision.

Good luck, and I'll be thinking good thoughts for a positive outcome.