Hey Chynna,
I am sorry that happened to, however, it's not your fault. I have had to fire many people over the years and many times it is sad. I had to fire my older brother when he worked for me, and that was most difficult.
The Peter Principle: Everyone rises to thier level of incompetence and remains there.
Eventually everyone gets promoted to a job they are no longer qualified to do. Everyone reaches thier level of incompetence. However, sometimes people are able to use their own set of tools to get elevated to a job that they are not only incompetent at, but actaully just are incapable of doing.
Sounds like you did everything you could to help this person become sucessful and they either lacked the desire or the skills to do so. You have a job to do also and when those under you, that you delegate, do not perform, it is the same as you not performing. "The delegation of authority is the same as having had done it yourself". At least as far as your superiors are concerned.
As long as it did not get personal, which it did not, it's just a bad situation. Again I am sorry you had to experience this.
Love always,
Elizabeth