She will act a lot differently around you then how she does around other people. Maybe give her a soft tickle, and if she tickles back and flirts then she probably has a thing for you. And yeah she will laugh at all you're jokes, even if there super lame. Or you could just be all front up and ask her what her feelings are. Goodluck.
Girls actually open their neck more when they are attracted to people. Not physically cut open their neck, but will tilt their head so more of their neck is exposed or flip their hair out of the way. They do it without even noticing. Little know fact. Watch other happy couples and you notice it.
Ima girl and when i like someone i flirt with them like joke around, be myself, and just start a conversation, if u like someone and she might like you ask her out the worst thing she will say is no, hope that helped :)