Competing Adoption

Hi all, I'm new to this forum so forgive me if I'm in the wrong place. We're FP to a sweet little girl and have been her FP for a year (her whole life). We are in a competing adoption with non-relative adoptive parents of a sibling that live out of state. The sibling and our FD have not ever been in care together nor have they been a part of each other's life for the last year. Our FD has had no contact with them since she was a month old. She was 10 months old when they finally saw her again and she met them for the first time. They are refusing to understand that she has bonded and integrated into our family and to move her at this point would be detrimental to her already delayed development. We have child welfare on our side and they are recommending that we be the adoptive family. Has anyone experienced a competing adoption with non-biological family members and can share their story? Has anyone appealed a competing adoption and if so, how long did the appeal take? Biological parents have already been terminated and she is legally free. Thanks!