Well... it could be that she thinks YOU are telling her Who She SHOULD BE... because you keep telling her... "I am NOT your father..."
It could very well be in how you are phrasing the questions... tone, facial expression... situation in which it is expressed...
You can change all those things, if you want.
It's not about finding the answers. It's about asking the question. And if you don't find the answer that feels right to you... you need to ask another question, eh?
It's about the questions.
She can find Who She Is... and you can find Who You Are... and you can do it together, and it can be fun...