My daughter, who is 32 has long blonde hair with no problems until a week ago. She got a quarter-sized spot on her scalp with felt kind of goopy...like she'd used some heavy-duty product on it, but she hasn't. It won't wash out and it's now covering her scalp. I've never heard of anything like it.
She just moved from an apartment that had a really bad mold problem, but her doctor didn't think it was related. He had no answer, either. I can't believe the doctor didn't even culture it!
try washing her hair wish dishwashing soap, the really concentratd one. It will strip anything out of her hair and its wont do any damage, just wash it with that and put a deep conditioner on the end and see if that helps