So sorry your daughter is having such a rough time... I don't have too much more to add that others haven't already. But, do make sure that her school is aware so that they can take into account what is going on with her with regard to attendance and homework etc. When things are bad, just getting up in the morning can itself be an achievement. One thing that can help to cope, as she as a lot on her plate to deal with, is the removal of unnecessary pressures.
As Kevin has said, make sure she is taking the NSAIDs with food and stomach protection. I learnt that the hard way myself... I also appeared to be tolerating them ok, but ended up anaemic, and with the feeling faint/lack of energy that goes with that - specialists comment was that it was likely to have been caused as a result of low grade bleeding from the intestinal tract due to the medication. That certainly made me keen to get off them as soon as possible! While fatigue results from the body struggling to cope with the inflammation, if the faintness is a new symptom it is well worth discussing this with your doctor and seeing if they can run a few blood tests just to make sure.
I hope that you have a good med team that you can work with, and that your daughter gets all the help and care she needs. I can only imagine how hard it is to watch your child be in so much pain. Glad you found us here, although not that you had too.