Dog peeing inside.

Question
I have a maltese/west highland white terrier x. She is approximately 6-7rs old. I adopted her from the pound 3 years ago and she has been perfectly toilet trained and was very well behaved up until last year, when a young male puppy became the newest member of the 'pack'.
She cocks her leg and wees everywhere- when no one is watching. I have tried sprays that deter dogs from peeing, I've tried taking her to the toilet several times a day.
As it's not my house, I have been told I am no longer allowed to keep her there.
I guess that she is trying to state her order in the pack, but what can I do about it? Please help!

Answer
She is not doing this because she has to go to the bathroom; she is marking, Rebecca. I recommend keeping her in a crate when no one is home or when you are too busy to keep an eye on her. When she IS loose in the house, use baby gates to keep her confined to the room you're in, so she can't sneak off and go to the bathroom out of your sight. Using a doggie diaper so that if she DOES try to pee, it will not go on the floors, can also help in the event that she does get out of your sight. You will need to keep the diaper changed just like you would a human baby, though; she should not have to run around wearing a dirty diaper. When you catch her in the act, scold her and tell her "NO. OUTSIDE" and immediately take her out. If you just happen across a place she's peed, just clean it up. Scolding her after-the-fact will do no good.

If she is not already spayed, that may help.