Attached to Baby

I had to return to work and my daughter has been in in-home care with a sitter since the end of April.  She turned 7 months old yesterday and weighs about 14-15 pounds.  According to her ped. she is growing both in length and in weight just fine. In the past I have had issues with the sitter not thinking I was giving her enough milk during the day.  I have increased her intake some, though I didn't feel that it needed to be done.  Now I am hearing this again.  I nurse my DD twice in the morning before taking her to the sitter.  She eats around 6:30ish.  At about 8am she has 3 tablespoons of rice cereal mixed with a whole banana.  At 9am she has a 3 oz bottle, at 11am she has another 3oz bottle, at 1pm she has a 4oz bottle and at 3pm she has a 3oz bottle.  Then in the evening with me she nurses however much she wants.
The sitter keeps comparing her intake to that of a formula fed baby because that is where her experience lies.  She formula fed her three children and has never kept a breastfed baby.  I have tried explaining that this isn't a good comparison because so often formula fed babies are overfed and they actually need more per feeding than a breastfed baby because formula doesn't have all the "stuff" that BM has in it for baby.  Based on my research (places like kellymom.com, askdrsears.com and the LLL website) and what I know about my DD, I don't feel that she is hungry.  I think there are other reasons that she is having bad days with the sitter...ranging from her simply missing mommy, to her gums bothering her-she just got her 2nd tooth on Friday, to her being tired because some days she just doesn't nap well.
Has anyone had an issue like this and have any advice to offer.  I am really at the end of my rope with the whole thing.  I wish more than ANYTHING that I could afford to be home with my DD, but it just can't happen right now.  We are working hard towards it, but I don't know when that could happen.  I am just so frustrated because she thinks I am not giving my child enough to eat and I don't believe this is the problem.  It just serves to make me even more angry that I can't be home with her and it makes me furious that this begins making me question my abilities as a mom!!