I always used soda water, but we've only ever had dogs not bitches. The vet gave me a solution of something that was a very common thing but I can't remember what it was when our old Lab was a bit forgetful. Not bicarb but similar.
And don't whatever you do, use biological washing powder, we made the mistake of this and it stripped the colour out of the carpet!
My advice to you would be to get a professional clean done on the carpet, when our dog weed on the carpet this was the only thing that got the smell out