Are you sure she isn't a few months older and starting her season? Her vulva will be swollen and oozing blood continually if so.
If she is old enough to be coming into season, she should have all her adult teeth. At 5 months, she might not have her adult canines.
No matter what, a vet visit would be good. Take any medical records you have. Discuss having her spayed when the vet thinks it is best.
Check the sticky starting at
http://www.askmehelpdesk.com/dogs/in...tml#post251802 Don't expect housebreaking to be successful until you have any medical problems in hand.
I have asked to have this moved to dogs.