I think if it's something you want to do passionately then you can make it happen. You are very pretty so just go for it!
Pin up modeling is open to girls of all shapes and sizes which is what makes it so diverse and wonderful. I started dressing up and getting friends to take pics of me (I even did my own shoot in my bathtub with my camera on a timer because it's the only place in my house with decent lighting). Once you get some good pictures of yourself you can get a profile on Model Mayhem to network with photographers in your area. Just set your first goal, once you reach it set another and so on. Good luck chicka!