Hello all!! I’m a mother of one 7, soon to be 8 year old girl and my Fiancé has also has a daughter who is 5 years old.…

Hello all!! I’m a mother of one 7, soon to be 8 year old girl and my Fiancé has also has a daughter who is 5 years old. Together we have a baby on the way and I plan on buying them both a big sister book. However, a lot of these books talks as if the big sister in the book is having a little sibling by both parents. Obviously I’m not her parent nor do I want her to feel like Im wanting her to call me mom and replacing her mother. She’s extremely shy beyond words and hasn’t quite taken to me and I don’t want her to feel uncomfortable. So moral of the story issssss.... Are there any children’s books on being a half sibling by any chance? Lol I’d appreciate it. Thank you