How do u get a girl to like u with out her knowing

she is ur friend

Without her knowing what? That she likes you or without her knowing she's being manipulated?

There is no sure way to "get" (or make) someone like you. What causes people to be attracted to each other is so complex that what attracts one person may repel another. My advice would be to hang out with her and be as much fun as you can. Beyond that, if the chemistry isn't there, there's little you can do to change it.