It's okay for you not to be okay with that. That is your truth and where you are at. It is fine to tell your bf that.

Also, his daughter is an adult and no longer a child. She misbehaved and has not apologised. I think it is time for frank discussions all around.

It is not okay for her to be disrespectful to you. Again, she is not a child, she is an adult and at the very least, ought to behave like one.