No. She is not disability. You shall know that disability mean people who can't action normally. Since she has one eye, she can see thing as most people do. So, she is not disability. She is just a so special person. You shall convince her that she is not disability but normal person. Also, you shall teach her to face the gossip and just do herself.
It is so strange. Why your girl has only one eye? Is her other eyes damaged? As far as i know, being blind in one eye is not qualify for social security disability. But things are different between children and adults. But this is not the matter of you concern. You shall help her to be confident and face the gossip from others.