She sounds fine to me. I just have one curious question. When her father died, was it due to the death of Megan and the Great Death or was it due to something else?
If it was due to something else you may want to mention that his death happened before the Great Death since he and her mother were both Ponies of Light. Also, what happened to her mother? You mention her father but not her mother and that makes me curious.
I don't really think that seeing 50ft away is a "power" so, if you want her to have a power you still can. She doesn't have to have one either. Just note that, since she is 20 years old, I don't think she would discover one at her age. It could just be she doesn't use it and if/when you want her to have one (if you don't decide now) you could still add one at a later date. It would have to be submitted for approval though.
So, basically give us a bit more detail on her parents, and let us know if you plan on her having a power or not.
She sounds cool! Do you have any idea where you'll want to play her?