Sorry if guys aren't allowed. But I'm a guy. I have 2 kids with my partner. Only 1 is biologically my child. The daughter that isn't biologically mine is 4 and a half years old . I have played the father role in her life from when she was 7 months old. Her dad wanted nothing to do with her. We have took him off the birth certificate and changed her surname to mine. I have been told many different ages to tell her I am not her real dad someone told me to tell her at 5 and someone else at 15. Any help would be very grateful.