It can deffinately be a trick to get them to flare their fins. My female regani just has to get her tankmates near her, my spec. 'wallacii' normally flare during feeding. My orginally noto's almost never flared though, except when the males met each other in the tank.
Deffinately a lot of regani morphs (tapajos, tefe, amazon, mamore/guapore are the ones that come to mind, but I know there are several more). Xingu used to be considered one, but was split off onto it's own, undescribed species. I imagine that will happen to a few of the others as well. Your female looks a lot like mine, which I believe to be the amazonian race, but can't be 100% sure without collection data.