She sounds so much like my golden retriever I just lost at 14 years 5 months. Same thing, trouble getting to his feet, difficulty walking or walking but not for long, paw turning under, arthritis, dropping stools indoors or while sleeping, and also bladder incontinence. My dog also took a glucosamine supplement and I think it helped. Here is a website listing physical therapy exercises for arthritis you can do at home.http://www.marvistavet.com/html/arthrit ... _cent.html
Good information here, too.www.srdogs.com
Have you considered maybe trying an anti-inflammatory, or a pain med to see if it makes a difference?
At this point you may want to start looking at harnesses to assist you in helping your dog to her feet. There are a number of harnesses on the market, some can be worn all day. Some people like the Lift and Assist harness sold on this website. The Hartman Harness (http://www.hartmanharness.com
) is another all-day harness.
I hope you will think of yourself at this time, also. If you are not physically able to lift this dog, that is not your fault.