Is it possible that she just doesnt have full control of her bladder yet?? I have a puppy too she is 6 months old, she only pees outside, we have very few if any accidents...
BUT: if she heres a weird noise and gets barking like she is scared , she will pee where ever she stands and the last time was on my couch.. but she was scared and barking and running back and fourth to protect me

, it has happened a couple of times but when she is nervous and barking, like the pee was scared out of her...

I just think she looses control when she is nervous!