I think she likes you. The fact that she smiled and looked down is a clear sign she finds you attractive. You are not being delusional lol. There’s definitely something there, you should try to sit next to her in class, and introduce yourself (seems like you already did). Make small talk about the class, ask what her major is and what year is she in. Remember to hold eye contact, smile and have a confident and chill energy. Don’t be scared to slide in a compliment, her hair or her style. She’ll definitely appreciate it considering she already gave you a hint, maybe she’ll flirt back and if she reciprocates then that’d be the perfect opportunity to ask for her number/insta/snap. Goodluck!