What should I do at this point?

One of my best friends is really immature. I tell her like tons of stuff and she will just look at me like, "wow!"...if you get my drift. She is kind of well, childish. If I talk about a guy to her she gets a little nervous giggle. it is so weird. And the movies she will watch are really like for like young kids! I will talk to her about the movie sweeney todd (i have a thing for that movie lol) and she doesn't listen and when i am done she will talk about a movie like, the cheetah girls! What should I do?!