There are several meds used to control Lupus. Plaquenil helps slow the disease. Prednisone (which is a steroid so she won't be using it!) is generally used to control inflammation. There are some other options to control inflammation that are used less frequently because of the side effects.
Then there are a handful of meds used to try & "quiet" disease activity (Rhemies tend NOT to use the word remission) - Imuran, Cellcept, and MTX come to mind.
Have you read about
how to diagnose Lupus? You need to have 4 of 11 symptoms, see
https://www.lupus.org. The vomiting sounds like maybe another more GI-oriented auto-immune disease, like maybe Chrons or something? And I know there are some auto-immune clotting diseases as well, but don't know much about
them.
Best wishes