I would just keep an eye on it in case things get out of the ordinary, like the bump getting larger or her habits changing. Like I mentioned, a bump can be so many things and only a vet can truly diagnose the cause. Hopefully it's a harmless bump.
If she continues to not poop for you, try using the warm honey bath method. You should be able to search it, but it's pretty much what it says on the tin: use warm (but not too hot) treated water with a few drops of honey and soak him for up to 15 minutes. It might take more than one try, but it worked wonders for my pacman when I first got him.![]()