Hi, my husband and I are new and first time parents over 35yo. Our daughter is 2yo now and has been attached to my sister since 6mo old. She was born in the hike of Covid, year 2020, so it was really only my husband and I caring for her until about 4mo. All of a sudden after my sister began to come around to help us out, our baby formed this really overwhelming attachment to her. Its so bad to the point she doesn't even want my husband and I to touch her when my sister comes around and she acts like that with my mom, her nana as well. My mom is her caretaker since 16mo old but she will turn on her as well when my sister comes. When my sister leaves from visiting we catch pure hell! This is really getting to be an issue especially since we thought she would have grown out of it by now but its getting worst.