She's still young then. You can wait until she's about 6 1/2 months old to see if that tooth will fall out. If it doesn't, then a vet visit is necessary for sure.
In the meantime, I said you can try to wiggle it a bit. GENTLY. Don't actually try to move it all over the place or pull it if it doesn't seem to be loosening up--if it is not falling out on its own, it may still have a longer root than it should (the roots of baby teeth start to resorb during the process of teething--that's basically the reason they can fall out when it is time) You definitely don't want to risk breaking off the tip of the root in the dog's gum.
I am not a vet though. I've had that happen with my dogs, but I'm not actually looking at your dog to see what is going on in his mouth. If you have any questions and are concerned or if it looks like there is inflammation or sore spots developing, go ahead and check with your vet. They're the ones who are trained and there in person, after all.