Nope--nothing is wrong with a girl that has some facial hair. Sometimes, it just takes "biology" a little while to adjust in our bodies. Men grow facial hair because of natural hormones in their body. The hormones are in a different balance in men than they are in women and that has a lot to do with why we look so different. This also is relevant to Miguel's question. Anyway, sometimes, as our bodies begin to "balance" these different hormones, they can cause things like facial hair to grow on a girl.

We all have hair just about everywhere on our bodies except for the palms of our hands and soles of our feet.If you look closely at each other's faces you'll see lots of fine hairs even though you're probably all way too young to shave. All mammals have hair. Even whales, which don't have fur as adults, have hair before they're born. We have about as many hair follicles per inch on our bodies as chimps do, it's just that our hair is short and fine. (Why do you think humans have so little hair? Why do we have so much hair on our heads?)

Of course, what you're really asking is about more obvious hair. Whether the hair is obvious depends on things like what color it is, how long it is, and how much of it there is. A lot of women and girls would have obvious facial hair, but they are self-conscious about it, so they get rid of it. On the other side of the coin, some adult males don't have much facial hair or only have it in patches. To answer the last part of your question, there's a lot of normal variation in hair on both males and females. Why do you think males usually have so much more facial hair than females? Why do males get facial hair, then lose hair on their heads as they get older?

There's absolutely nothing wrong with them. Some girls could have more or darker hair growth in the face than others because of different reasons.

-First, heredity : some people tend to be more hairy than others, and their children will have the same tendency. Even for men, you'll see differences in the darkness (black or blond hairs) and amounts of hair in the arms or legs in between two men, but, there is nothing wrong with them.

-Second, many of the differences in between boys and girls are due to some substances produced by our body (they are called hormones). Those hormones are present in both boys and girls but in different amounts, and these amounts also change during our lives. So it happens that some changes in these amounts produce some hair growth in the face, and that can also disappear as it appeared.

So there is really nothing wrong, we are just all different.