I think your childhood friend is uncomfortable with who she is, maybe not with who you are. She thinks she has the answer and wants to impart that answer to others who do not share it, but like you said, what does it matter how we live our lives as long as we are doing our best. If she was truly comfortable in her own skin she would not have behaved that way towards you and she would have been able to listen and learn something from the path that you have taken.