If you are planning on spaying her they may do her teeth pulling then. So will only have to be under once. My vet and I watch the teeth and try to wait until they are a year, but if any tarter starts building up that is when you might want to consider doing it earlier, as it can effect her adult teeth. Give her a good nylabone(sp?) or something of that nature for her to chew on and this could help the milk teeth to drop out on their own. If she is not in pain and is eating well and no tarter is building up, see if nature will take it course, but don't let it go on for too long.