I don't know what to do

So.. My sister and I are pretty close and all but recently I feel disconnected in a way. So basically two years ago she wanted us to come and do school where she is and shw thought it would be easier and less pressure on my dad in terms of school since my parents are divorced. So we went on doing papers, telling the schools about us and after that we didn't hear anything about it. Then the following year she wanted my dad, my little brother and I to apply for Visa's. We went and did our photos, my school even gave reports and grades for both my brother and I and everything was fine. She didn't get back to us about the Visa and went my dad tried asking this year she kept avoiding the conversation until she came up with a response saying at first that her lawyer is looking through then she said we don't have the same mother so it's a problem (that statement on its own actually hurt) but the thing is her husband has been getting his parents visa, his sister and her daughter too and currently the sister is living with my sister and her husband. They just keep asking my dad to assist his parents but they never talk about the plan for us.

So then we kind of distanced ourselves from her but my dad was the one talking to her here and there

My brother and I didn't talk to her for almost two months until he decided to break the ice

But I still haven't said anything. She tried to message me but I've ignored it, until yesterday when she was on a call and said to my brother she thinks that I'm angry with her and my brother told her no and that I have exams and I've been studying. She then asked if I don't have any few minutes to spare to talk to her

So I don't know if I'm in the wrong here

But also in a way she kept telling my cousin and I that she wants us to come to her side for Uni and all but she's just been talking to cousins and other family members and avoiding talking to us