That is a reality best planned for. Also the reality of the polyship ending. And your role in the child's life after that as the non-bio person. If you want to maintain a parental role, are the papers drawn up so? As her godmother? Or similar? What about if the partner's have accident and die? Do you get custody of her? Does she shoosh over to Granny?
Very important. Something we established prior to ever being poly. Things to really consider before having children even if you ARE NOT poly.