One thing to keep in mind is that gifted children are famous for taking great leaps in their development. So it's great that you are preparing yourself for any future problems that might develop, but for now there isn't much to do - except praise every tiny bit of self-control you see in your DD3. Praise all the sustained focus you see, even if 'sustained' only means a full second.
(More in 'Transforming the Difficult Child Workbook' by Lisa Bravo if this approach interest you.)
I would firmly maintian the unspoken attitude that all my children are equally bright, but are using it in different ways, and therefore there is no need to make comparisons. The point of humans is that although we are mostly alike, that is also what Spock from Star Trek would call: Infinite Diversity in Infinite Combinations
The theme of "Infinite Diversity in Infinite Combinations"is symbolized by the Vulcans in a Kol-Ut-Shan,[5] represented as a pendant of yellow and white gold with a circle and triangle resting upon each other, and adorned with a white jewel in the center.
I call it: 'Every child IS a gift.' Your oldest's and youngest's giftedness seem to be taking fairly convential paths (for us here, LOL) and time will tell where DD3's path will lead.
Love and More Love,
Grinity
