[3a] is a mechanical engineer. Originally, she was to be part of Ɬare's team - identifying technological trades with the species found at the other end of those muddled artificial radio signals.
She was also on the consulting list when the ship arrived in the Human solar system, converting the toroidals from storage to living and working space, using technologies that the local species would not yield huge benefits from if it came down to a five finger discount.
Was called in when [Subject 3] was proved to have psychological damage that would not allow the manifestation of full limbs - a fairly foreign concept to a species of obligate shapeshifters. Too injured to shape a limb (when you previously could) would put you on the edge of death.
During interactions, [3a] and [Subject 3] spent a lot of time researching and improving current human prosthesis designs. After [Subject 3]s anticipated expiration, [3a] continued to work on these designs, wearing and testing the incremental improvements daily. She has the ambition of leaking these designs - against mission policy - before the ship returns to the homeworlds.
[3a] was recruited to be an engineer before she was fully grown- at least that's what she claims, as the tinges of royal blue would suggest things otherwise. Spacer purple from "Child labor" is not seen as a problem on Iu'husid - so long as you aren't natural-born. The other planets, Calcaei and Weltra, have laws against this. But Royal Blue... that's seen as an indicator of genetic tampering or a decendant of dictator strains.