Hope I didn't overstep, but I had a sudden inspiration for some NPC students that could be part of this.

Two pairs of twins, each pair born of a mother or her twin sister, all with the gift. Their family lineage comes from the Elementalist traditions and were inducted into the Order, their entrance fee was to provide Gifted children.

So we have 4 children whose mothers are themselves twins, and each of the children is strongly attuned to one of the four elements and fostered by a different House. There would likely be some uniformity in their Virtues and Flaws, but their House choice need not be too obvious (the fire favoring child does not have to go to Flambeau). I'm thinking they would likely have the Elementalist Major Virtue, Puissant Art or Affinity Art with their chosen element, and perhaps a Supernatural Virtue, like Greater Immunity or Latent Magical Ability. Flaws could be weaknesses in the opposing Forms, or Necessary Conditions and Study Requirements.