I have found the same thing as txshopper73 - my two girls came into heat for the first time at 10 and 11 months - but every littermate to one of them came in at 6-7 months so it just varies. And they tend to pee more when they are coming into and during their heats and I think she is right - I hadn't thought about it but it does seem like they are marking their territory.
As far as the barking goes I would also like to know what might work - mine also bark alot!! They have gotten better as they have gotten older but still...
