Suggestions…

My daughter is now almost 6 and her father has never been present in her life. She has grown up with my father raising her and stepping up as that fatherly role. She addresses him as “ Papa” but she tells everyone that is her dad and she believes that is her dad. I am now expecting a new baby and she is asking if my dad will be the baby’s dad as well and I really do not know how to explain to her how my dad ( her papa ) is not actually her dad. I feel heartbroken and she is very very sensitive and the last thing I want her to feel is like she did something wrong… what is an age appropriate way to break it down to her or should I just wait until she is older to explain to her?