K., I am so sorry to hear of that your family is sick. My son contracted RSV when he was four months old. He had a nebulizer and we had to use it every 6 hours around the clock for four weeks. (We still have to use it when he gets sick sometimes.) It was a pretty horrible time. He seemed much better after about two weeks, but their lungs can take it pretty hard. My doctors told us that my son would probably always have respiratory problems, and this has been true.
I think mostly your daughter needs a lot of support. It is exhausting to give those treatments every 6 hours, and it will require a lot of time away from work, or some time resting if she stays at home. If your daughter works, I would suggest her getting something in writing from the doctors, which I didn't do. As a result, I was forced to resign from my position on staff (at a church!)because the doctor also did not want my son going back to childcare for two more weeks after treatment, and I was told this was not an option from my place of work.
Nonetheless, they will get through it...my little baby got better, and your babies will too.
Prayers and well wishes,
H.