She will be happier - and, ultimately, so will you. Having a brother or sister with a disability can be hard on siblings - especially in those teen years when peer acceptance means everything. A sibling with a disability can add an extra burden to a teen who is struggling to find an identity, who is trying to reconcile his need for independence with his fears. Anything out of the ordinary becomes threatening, even weird. Unfortunately, this can include a teen's sibling with a disability.
Friends can be cruel.
Worse, your able-bodied child might feel embarrassed by his own brother or sister with a disability. He might feel angry and resentful - which can lead to confusing feelings of guilt. Don't ignore the fact that the disability exists. Talk about it in everyday, ordinary terms with your family. Recognize that your able-bodied children might get some added stress at school or among their friends because of their sibling with a disability.