Hi Gerbil,
I’m sorry to hear about your situation. That must be really upsetting for you to hear. As you said its understandable due to abuse she witnessed and experienced from her dad. None of it is your fault however and you are not responsible for his behaviour. Its okay to still acknowledge her feelings and what she has been through.
It sounds like she may need some time to process things for herself, you can encourage her to reach out for support or perhaps counselling if she feels ready. You can be there to listen but don’t feel you have to take ownership of what happened and what he did.
Take care and keep posting
Lisa