Maybe you could try adding some chicken and rice to her food and some veggies and carbs.
Brownie can get a little skinny at times and I just add chicken and rice to his food and it really helps put weight on him and he just loves it.
Have you tried the satin balls? They are suppose to be good for putting weight on them.
http://www.yorkietalk.com/forums/yor...tin-balls.html