Hi tryingtosleep,
Thank you for sharing with us, it sounds difficult for you and your daughter. You are right, your daughter does not have to do anything she does not feel comfortable with. It is understandable you want to protect your daughter.
You may find these organisations useful to explore how to deal with this- Family Lives: https://www.familylives.org.uk/, Gingerbread: https://www.gingerbread.org.uk/, NSPCC: https://www.nspcc.org.uk/
Keep posting when you can,
Best wishes,
Lisa