How about taking a deep breath, and tell her that you like her. She might be introverted, and sometimes shyness accompanies introversion, but finding out what she likes is a journey she should make on her own, shy or not. Knowing that you like her will force her to think about her preferences, and then she gets to come to these conclusions herself (maybe not right away, but eventually). Risky, for you, of course. But I think it's the best way to to be fair to her.
Take the risk of thinking for yourself, much more happiness, truth, beauty, and wisdom will come to you that way. - C. Hitchens
Me: Male, bi, 48, flexible