My crush’s sister hates me

So me and this girl have been talking to some time now, we obviously like each other but whenever I ask her to hangout she comes up with some excuse. Recently I asked her again if she wanted to hangout but she said that her sister hates her for even talking to me so she wouldn’t be able to hangout. I know that her sister used to like me and I kinda avoided her without being a complete dick. Whenever her sister is around she kinda acts a little cold to me, but when we’re alone it’s like she’s obsessed with me. Another thing is that she’s going to another school in two months, I tried to get in but they wouldn’t accept my application, so I have two months to make a move. I have no idea what to do, I really like this girl but there are just so many obstacles. I just can’t imagine her going to another school miles away where there are hundrends of other guys, she is someone I’ve never met before and she is really special. Can someone please help me. I’m literally torturing myself over her.