Ｉdon't know if your daugther's symptoms are the same, but I have positional vertigo (the room spins when I lay down or turn around in bed) plus migraines. When I get migraines they're atypical and not just on one side. They don't come on as severe as for some people but they can be at times. Most of the time they happen at the same time (or used to), now the migraine's happen more frequently than the dizziness.   I found out after 4 years (2 going to the doctors) after doing research myself that it's Migraine Associated Vertigo (MAV) or what's also known as Vestibular Migraines.   For me, the migraines are weather related to the weather. Shifts from cold to hot back to cold in a short period of time. Plus hot weather triggers migraines for me too. Hope this helps!