Thanks- I'll look into them.I believe it is Varsity Vet off Edgewater just south of Princeton.
Could be a Luxating Petella. Very common in small dogs. Our Yorkie had it, and she required $1200 surgery to fix it.
http://en.wikipedia.org/wiki/Luxating_patella
I'll keep that filed away, though it doesn't appear that's what she is experiencing.
She has been better yesterday and today. Interested in playing a little, able to get up my front steps on her own... she seems to be on the up-slope. I did notice a dime-sized sore on the inner part of the problem leg. I'm wondering if that has something to do with it.