just as long as you aren't a skinny fat girl. That would be a girl who is skinny because of genetics and/or diet but does not get proper exercise. If your that size and weight and get proper exercise then don't worry about it I'm sure your body looks good.
Supermodels are thinner and taller than you. They grace the covers of every high fashion magazine. This is the look for this time era. If you're naturally slim, then why fight it? Lots of girls want to have a body like yours, but cannot.