Ugh. My son was hospitalized (1 day in PICU, 3 days regular unit) with RSV as a 6 month old, so I feel your pain. Good that she's having wet diapers.
its so hard for them to eat because of the breathing. DS's intake was less than half of what it normally was (I EP'd),
the good news is that BM is easier for them to drink. Not sure if you'd ask the pediatrician, but DS took alot more fluids when it was BM cut to half strength with pedialyte since its even thinner, and if its in a bottle, its easier for her to take. The nureses were OK with less nutrients since its FLUIDS that they need the most to avoid dehydration. DS did end up needing IV fluids though. Keep a lookout for dehydration by watching the colour of her legs. if they looks splotchy, and if you press look for how fast the colour returns as an indication. Also keep watch for retractions while breathing and the respiratory rate.
Good luck, I know how much they don't like it, but suctioning before a feeding will help ALOT. Also, watch for fevers. RSV is up and down, they seem like they're doing great and then things turn around sooo quickly.
I'm soooo feeling for you.....hope you don;t have to go to the hospital!
Edit: Oh! and I'd consider adding a pumping session, to keep your supply up! Bon courage!