She'll more than likely take advantage of the fact you're attracted to her and ask you for favors and shyt. Then she'll really lose respect for you because she see's you as nothing but a desperate dude who has no other options, and keeps hangin on while she's fukkin other dudes. I mean you can try and get at her friends but the second she tries to get you to do some favor and give her money, you'd better say hell the fukk no with the quickness and walk away.
Females have egos just like guys do so if you allow them to use you for an ego boost by continuing to try and try with this girl, then she feels herself more while your self respect plummets.