Sometimes I would dream about girls I had crushes on and this sounds crazy, but how they acted in their dream would oftentimes tell me how they feel about me in real life. With one particular girl for instance, she would always ignore me or pretend like I didn't exist in my dreams. This later turned out to be true as when I finally got the courage to ask her out after class ended, she ghosted me and never talked to me again as apparently I creeped her out.
Another girl, I dreamt I was at a giant cafeteria and I was watching a video of her making love to another guy. I then sit down right beside her, she completely ignores me while talking to another group of friends, and later gets up to leave without saying goodbye to me or acknowledging my existence. The dreams ends when I am chasing after her but can't find her. Later in real life, I was at a bar and I saw her there. She completely ignores me to talk to her friends. Later, I see her making out with another guy and going into the bathroom with him. She leaves, without saying goodbye, or acknowledging my existence.
If you don't know whether or not a girl is into you, if you dream about her, how she interacts with you can be a tell-tale sign. Because your sub-conscious picks up signs and signals you may be completely aware of, and then it translates to your dreams.