Hey there! Just wanted to let you know that that was my original diagnosis, and I was also on mtx for sometime. It can cause nasuea, but the folic acid helps some with that, and they should give her a pill she can take when she actually feels sick. Those work wonders. Aside from that, mtx was my best friend for quite awhile. I hope it works for your sister, and I'm glad to hear that you may have finally found a good doctor for her!
Lots of Love!
Lupus, Rheumatoid Arthritis, High Blood Pressure, Anemia, Congestive Heart Failure, Kidney Failure