My daughter had two severe migraines 3 months after starting yaz (drospirenone and ethinyl estradiol). should she stop taking it?

Possibly : If she has never had migraines in the past they certainly may be triggered by the hormones. On the other hand some people see relief of migraines when their hormone levels are kept more even with contraceptives. The only way to know for sure is to have her stop for several cycles to see if they return. Coordinate a plan with the prescribing provider.