My daughter's natural father was never told

Answer 1

 This thing is very much justifiable because the thing which you never know is never there to be told. 

Means your Daughter is all yours give her as much love as possible. She should never left to feel that she does not have a father. 

Though it is a very hard thing in this world because when she will socialize then certainly she is going to ask a lot of questions but still reality cannot be changed.

Live in the present while looking on future which is about to come. Past is never there it is usually a gone story.