It changes person to person, but that's not too much and it sounds about right. I go on IV antibiotics roughly twice a year. Usually on my Christmas break from school and again once I get out for the summer. Benefits are pretty big. If I'm growing infections and don't find drugs that work, I cough twice as much, I wheeze all the time, I have trouble with stairs, I can't laugh without choking, etc. After the IV drugs, I just feel better all around. It may sound stupid to people, but having to tell my boyfriend to stop being funny because I'm too tired to cough for 5 minutes afterwards really depresses me. I much prefer being able to laugh when he's being a smartass without having to worry about it. Actually, in all honesty, it depresses him too when I have to tell him to stop being funny. There's just a lot of little things. And yes IV antibiotics can be a pain in the ass, but if they fix the problem, they're worth it. I know this may not be comforting to her, but if she's only starting this now, at least she had a "more normal" life than most of us. Haahaa. I've have to work my IV therapies around my vacations with my family and my boyfriend's family and around my college schedule etc etc.
But anyway, they tend to fix the problem, and as awful as this sounds, she'll get used to it. It's a hard diagnosis to take late, I'm sure. I've known since before I can remember, so I can only imagine. But I gather it must be scary and junk. She sounds to be doing pretty well though, so rock on!