As someone who has drawn for years and has read tons on the subject and about teaching other people to draw... I think pretty much anyone who can write their name has the "ability" required to draw. It's just that people don't know how to get into a mode that allows them to draw effectively. I read a fascinating book that talked about a child's artistic development, at what age people stop drawing and why, and about teaching people to draw by activating the right side of the brain. As it turns out, most people stop drawing at age 12 because of a growing sense of dissatisfaction with their drawing abilities because they're drawing on the left (dominant) side of the brain, which tries to throw symbolism onto the subject they're trying to draw (for example, they try to draw a human face, but the eyes are massive and up too high on the head; this is because eyes are extremely important in human communication and so they are important to the drawing, and so, without realizing it, the child transfers this all important symbolism into their drawing, leading to things "not looking right" and inevitable frustration). I'm working on trying to build a system for teaching private art lessons, and I'm especially trying to get this one particular girl to take lessons who is completely convinced that she can't draw.
It's true, some people are much better at it than others... But you're probably not as incapable as you think you are!