Teen relationship help?

Hey, I'm having a bit of trouble with my girlfriend. We've been seeing eachother for about 1 and a half months now and she's constantly too busy with her friends or doing other stuff to hang out with me. We've only hung out 3 times since we started seeing eachother but she still texts me every single day and whenever I ask her to hang out she either says she's too busy or too tired. I still like her, but things are always kind of downhill since the start. Any advice?