How do I get this girl to ask me out?

Anonymous
There’s a girl in my college class who I’ve recently noticed. I recently did a presentation in the class and she was really engaged with it and answered my questions when most people didn’t which I found nice but I didn’t pay too much attention to it because she’s usually very outspoken in class and very smart.
After my presentation she shared a piece of writing that went with my presentation and went back and answered one of my questions that the writing applied to.
Yesterday I was sitting by the door in class and she was approaching the classroom and was walking down the hall. I saw someone out of my peripheral and looked up and the girl and I made eye contact as she was walking in and then I looked away. She was kind of late so she sat near me ( not directly behind me but like diagonally behind me ). After the class was over the professor asked her a question as she was leaving and she stood right next to my seat to answer it and knelt down a little close to me which I found weird.
I don't know the class will be over for the semester soon and I’ve really came to terms with being bi and want to get to know her better. The only problem is that I’m femme and no one knows in gay. I’ve been told I’m straight passing.
Also I’m not sure if she’s gay. She gives a bi vibe also and can dress kinda masc sometimes but she’s a femme for the most part. How do I do this? Should I keep making eye contact and hope that works?
How do I get this girl to ask me out?
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