Step parent advice

Im a step parent. I have been for about 7 years now not married but have been there since the child was a baby and with my SO the father. My immediate family sees me as a mother but the rest of my family doesnt acknowledge any of it. I recently just introduced them to my step daughter because of issues within the family and timing i never was able to introduce sooner. Well my uncle committed suicide and we had a service for him and my step child was able to go because it was our weekend. My step child did know my uncle before he passed. It was the rest of my family that i was worried about. Well everyone met my step child and loved her. But when talking to me most didnt consider me a parent like i had no say in what happened with her. They would ask me if it was ok to give her(blank) and if i said yes or no they would tell me to ask my SO or go ask him. If this was unusual within my family i woukd understand but its not. My dad is a step dad my uncle (hes not married to my aunt but has been with her for over 20 years they have one child together he has 3 from a previous marriage and my aunt has 3 from her first marriage which my uncle died from a drug over dose) raised my cousins that werent his. Everyone considers them a parent but not me and my SO doesnt understand why they treat me that way because his child sticks to me like glue and loves me and he has given me permission to make any judgment i see fit. They know i have been with him for years and that he had a child when we got engaged. How do i deal with this because it is something neither i or my SO is comfortable with