lol @ pushing her head down... Bro, you have watched too many movies, that is something you should NEVER DO (if you want to get some, that is)... if anything, you have to push her head up when is time to get into more serious things...
as said, talk about with her in a non-sexual environment (like when having dinner)... if it is not her thing, well, assess how important it is for you (more that the girl herself???). If yes, dump her...