My son had a major flare this past February after a dental cleaning and two teeth falling out/then almost immediately the adult teeth came through. It lasted several weeks and was the worst episode we had seen since the initial onset.
And my heart goes out to you regarding the intrusive thoughts--they were one of my son's hardest symptoms. He would sob in the middle of doing something or talking to us because they were tormenting him. Night time was the worst. He was so miserable and it took a long, long time for him to share some of the thoughts--basically he was afraid he was going to hurt us. I just kept reassuring him that there was nothing he could think that would make me or his father love him any less. And I kept reminding him that these thoughts were not him. I had him picture a stop sign in his head and then say to himself "I'm having an OCD thought about . . ." Also, grounding himself in the physical world helped. Tapping his feet slowly and calmly in a rhythm or focusing on three blue things he could see in the room and three things he could hear and three things he could feel with his hands--basically having him use his 5 senses to reground himself in the physical world instead of feeling trapped in his head.
It is overwhelming--but you will start to find methods that help her.