Want to gain attraction? Be an attractive guy.
There's no secret method. The actual 'methods' are just behavioral demonstrations that you ARE an attractive guy or atleast informed enough to mimic the behaviors of one.
Hit the gym, stop watching bullshit and start reading nonfiction books, invest in your appearance, your education, and your life experiences. Gain social capital.
Look man, when everyone here is going off on a tangent in paragraph form about one girl. What you should really be trying to work towards isn't you. IT HAS NOTHING TO DO WITH YOU. A lot of game has nothing to do with you. But the socially aware can ILLICIT and CREATE favorable environment and emotions that evoke a favorable reaction from the girl. This is where the brilliant strategists can separate themselves from the number games.
Look man, put yourself in full empathy with this girl. You're an okay looking girl, you spend 100$ a month or so on beauty products, you wear skinny jeans and yoga pants to highlight your 'features'. You really just want some validation, everyone wants some validation and approval man. It's just in certain personalities and characters, it's registered differently. In the one you're describing, she really isn't overtly sexual and she's just hanging in there doing nothing. This is where you can illicit emotions and behaviors. Tell her what she's missing, you know, do you ever just wish you could wake up next to a really hot guy cuddling in your arms? Tell me the truth, do you ever just wish a cool sweet guy who isn't an obnoxious douche-bag would come up on you and rock your world? Do you really not want to explore all the awesome rushes of young love and fun? You've seen the movie "The Notebook" right? don't you ever just wish you were apart of something epic like that?(I've actually never watched it so I might just be bullshitting LOL) Do you really want to be alone for the rest of your highschool life?
By the end of your conversation, you want this girl to feel like you're not just a random guy validating her hours of work and money invested into her beauty, but an opportunity to get all that she's been missing, fulfillment, excitement, an epic adventure. You're not just parading up to her, seeking her reaction to you, and then asking her to hang out with her so that you can bring her back to her lair and sexually assault her. You're creating a bond, a RELATIONSHIP that embodies all of these ideals and lusts she's craved for so long. You always need to realize what it is that you represent to girls, and play to your win conditions of those ideas.
You need to remind her of what she's missing in her life, and why you're the missing piece in the puzzle. It's just marketing and sales dude. If you're trying to sell a piece of shit, create a mist of air seducing aroma around the piece of shit that masks the smell for long enough for people to buy it. Think strategically on how to convince people of the value of the piece of shit. Hope that you're disciplined enough to evolve from a piece of shit into a Ferrari through your constant grinding and work so that you have to produce less seducing mist.
Can you guys tell I've spent the last 3 hours writing essays? fuck sake man