Stephania,

I've been with lots of girls smaller than you, some as tiny as 4'10" and well under 100 lbs., and though I've noticed some of these small-framed girls do feel a bit tighter, it has never been a significant issue and in my own experience the petite ladies out there can take a big cock every bit as well as the tall ones. In fact I've had the most problems with two ex girlfriends who were 5'8" and 5'10", respectively. Of course there's a chance it will hurt, but if you are more excited than nervous it probably won't.