You should know about every medication she has taken in the last week, and check each medication for interactions. Some medications can reduce the effect of mdma, others can cause the mdma to cause a lot of harm.
My own experience: Don't sweat when you roll, keep body temperature normal. Gives less hangover. (Elevated or lowered body temperature has caused brain damage in mice/rats when on mdma, the test subjects who had a normal body temperature showed no signs of brain damage).
Let her know she can feel a little down the first days after, and the first day she should not stress, just relax and be comfy.