I left him as soon as I found out I was pregnant and never looked back. I've raised Lily as a single mother, and she has always believed that my ex-husband, who I married and divorced when she was young, is her biological father. He knows the truth but has agreed to keep up the lie because he genuinely cares about her.

If she's old enough to ask the question she's old enough for the answer. Including your fears.

May you could tell her the correct story but being very insistent on the point of abuse and that he is a dangerous person. And didn't let her any personal information about her father allowing her to contact or discover her exact identity. In this way she knows the truth and you still protecting her of their father. Also it's true that some abusers are only dangerous for their partners, may he is nice with your daughter, but you cannot predict it.

Your daughter may learn the truth eventually through easy to do DNA testing, as I did. It would be incredibly painful for her to also learn that she has been lied to all along, especially when she is bringing her desire to know the other half of her heritage to you expecting you to be honest with her. I so wish my mother had been honest with me.

Be honest

Don’t lie. She’ll take a dna test. She’ll realize you lied. It will be awkward.

No and why do you have to ask

I think it will be difficult to come up with the truth now without scratches. This will hurt her because you lied, even if you wanted to protect her. She should find out now and in peace and plain language.

I would be honest, just in case she does a 23 and me dna test

Always be truthful. If somewhere down the road she finds out the truth, both of you may go through more pain, than dealing with the truth now.