Are you over feeding her? I had a similar situation but I don't think it was quite as bad as you are describing. I would fill buddy's bowl in the AM and he would just wolf it all down, ocassionally he would barf it up with out any fur balls. He's a long hair. I now regulate the amount of food that he has at any given time. He weighs 15.5 lbs and is generally let out for a few hours to roam his territory. I feed him @ 1cup of dry food each day, 1/3 cup in the morning, 1/3 cup later in the day, and 1/3 cup with 1 OZ. of wet food mixed in for dinner. Right now I am able to feed him 3 times a day without any inconvienience. Since I started this he hasn't lost it unless there is a fur ball in the way. He has also slowed down on his own as far as eating everything at one time. 1/3 cup 3 times a day is not much but seems to be the recommended total amount ( 1 cup a day) He gets a few of those fatty little treats that prevent fur balls at night when we're watching TV.
If she is eating birds and mice outside it might not be mixing well with what you are feeding her. It could be she is just eating to much.
Another idea would be that she may be allergic to whatever food you are using.
Hope you figure it out.
The required photo of Buddy
