If she's acting normal and eating normal, then she can't be that effected by the large tank. Typically, they will stress out with such a large enclosure, but if she's doing fine then why worry. My only suggestion would be to get some black Con-Tact paper (maybe two rolls for that huge tank ) from Home Depot for $6 and black out the entire sides and back. It will make it seem smaller from the inside. Nice looking enclosure, the clutter probably helps it seem smaller. If it works and you don't see any signs of stress then why change? There's no harm in a large tank unless the husbandry is incorrect or they go off feed really.