Are you talking about showing her in QH breed shows in the Hunter divisions or USEF hunter shows? They can be quite different.
I am curious about your mentioning Working Hunter/Eq prospect. In USEF competition, those are very different specialities, and it takes a lot of time and mileage to make an Eq horse or a Regular working horse. Also, it's fairly rare to see a QH showing Regular Working Hunter in USEF - fairly common to see them as Junior or Ammy Owner horses, or in the equitation divisions.
I don't know enough about what they look for in the AQHA hunter divisions to really evaluate her for that.
All that aside, she is quite lovely, and a good looking prospect. Nice mover and nice attitude. As she's only 3, I hope her wither will catch up with her hind end. At this time she's a little butt high, but lots of 3 year olds are.