What do you know about Urinary Incontinence?

My 21 mos old spayed shih tzu was just diagnosed with urinary incontinence. I believe her to have this condition for just under 2 months. When ever she jumps up or down from something I noticed she always stops to clean herself. After a while it got so you couldn't just think she was being extra clean. My vet has put her on 1mg of Stilbestrol. 1 pill for 3 days then 1 pill, once a week. The licking has cut down noticeably but hasn't totally quit. But then its only been 3 days of meds. Can anyone tell me how long it will take before I should really notice that these pills have done the trick. I will be taking her back to the vet in a month. I guess my real question is, will I notice results in a week? or 2 or should I go back to the vet earlier. Also does any one out there have another theory as to what it might be. In the urinalysis nothing showed up. A few chrystals but the urine was from 1st thing in the AM. Her dog food is Innova but another thing is that she sometimes sneeks the Low Protein food from my older dog. But shappreciatedet much. She isn't asking to go out more. Not drinking more water either. Any info will be very much appriciated. Thank you

She is cleaning herself after jumping because the dog thinks that its going to get dirty from jumping. Especially if its outside.