I feel awful😔

So I’ve been with my husband since his daughter was 5 months old. At this point in time he only had supervised visitation with her. A few months after she turned one he got to have unsupervised visitation with her every other weekend. He had a job where he worked through the weekend so I was the one who was keeping her while he was at work. We got close quickly and she called me mommy. Her mother didn’t like that at all and tried to get her to call me by my name but it wasn’t until recently that she has started to do that. She is now 4. I’ve always been a mother figure to her but I’ve never actually felt like her mother, more like a baby sitter for the weekend even though I did do motherly things for her. I do and always have loved her but it’s kind of like the love I have for my nieces and nephew. I did everything for her because her father was clueless when it came to taking care of her, not trying to put my husband down lol he was just a new father with no experience with kids. I made sure she had everything she needed while she was with us, she had so many clothes, shoes, toys, and her own room. I always made it her home too even though she didn’t live with us. When she turned 3 she started waking up in the middle of the night screaming for him mother by name. She started screaming and not wanting to come with my husbands sister/mom when it was time to stay for the weekend. She would cry all day no matter what I did to try to make her happy. I didn’t know what to do, she was once happy all the time with us.. I thought maybe it was just a stage so we powered through. I got pregnant in the middle of all this which made it extra hard because I was so tired all the time but I still tried my best to make her happy. When I had the baby my husband sister started keeping her on his weekends because I was so overwhelmed having never took care of a new born, much less a newborn with a broken collar bone and collic. After the baby was a month old we let her come over to visit him, she called him her baby lol it was so sweet finally seeing them together but we still needed time to adjust. When he turned 3 months old I felt like I was ready to take them both on. She came over that weekend and it was at its all time high of not wanting to be with us. She wanted to go back to my husband sister’s house. His sister gave in to her tantrum and took her home with her. We was upset and confused on what had just happened. It has been over a year since she has stayed the night with us. She has came over for a few hours and then left a handful of times. When my husband calls his sister and tells her that she needs to come spend the night his sister tell him that she won’t do it, she not even giving her a chance. I feel terrible, we used to be so close and now I couldn’t even tell you her favorite things to eat, watch, play with. I don’t even know what shoe size she wears, I have to guess and hope they’ll fit her. I just don’t want her to look back and think that we didn’t love her or that we didn’t want her, ya know? I don’t know what to do.