What does it mean you call a girl your sister?

Answer 1

If a guy says you are like his sister then it means he loves you. Not in a romantic, relationship kind of way. But he feels like he can talk to you and tell you things he wouldn't normally tell other people. He basically trusts you. You have been a good friend to him and he's very content with your friendship.

exactly; my sister has this weird relationships with her friends when her friends call her sis and she calls them mother, father, bro, or sis. Really they're all just friends though. If you asked her out before and she sees you no more than a loyal friend then she probably told you that to clear up your misunderstanding. It's best to just ask her of what she means. Don't worry, we've all been through this.