Super cool!
Nothing's really stopping you from using her in RP already, tbh. I'm simply sharing some SAINT knowledge because, much like making a normal Star Army character, there's a lot of new stuff to wade through and find on the wiki that may not be immediately obvious.
Was she raised by someone at Black Sands? Was she a regular Santo Hei who got sent to operative selection at Black Sands? Was she a regular soldier of some kind for years in the Star Army and then got picked to try and become a SAINT operative? I'm confused there because of the sentence that says
"her unique upbringing at Black Sands." Is it a situation where she got into SAINT training after basic and then her SnakePeople benefactors back home were like "okay, she can do this, we're not going to recall her to SnakePlanet"?
Just some general
information on training for your consideration: Every SAoY soldier goes through basic training (67 Days for non-NH bodies). Then, specifically for your character, they'd attend 6 months of SAINT training and then 4 weeks of officer training (unless they were an officer before being selected for SAINT training, in which case flip the two). Most SAINT operatives go through operative selection and indoctrination immediately after basic training, though regular soldiers and officers can apply for SELECT after already being in the service.
"Following the notable successes of Operation Nichibotsu, Himawari and Makruk, Aerlia was given the nod for advancement to Intelligence Officer."
Were these training operations? There aren't really half-SAINTs who went through some training and then wait for a spot in the fleet based on their performance. If you get selected and then make it through SAINT's rigorous training regime then you become an operative.
"Becoming a Shoi immediately following several anonymous recommendations from high-ranking personnel and foreign entities, she quickly climbed the SAINT food chain."
This part is honestly kind of iffy. I'm not sure how comfortable Wes would be with the "anonymous recommendations" of "foreign entities" having any impact on Star Army promotions, much less having sway over SAINT's business. Becoming a Shoi isn't the hardest thing in the world and mystery benefactors saying stuff might not actually help their career.
I'd still like to see some information on the pacing of her promotions. But it also doesn't really matter in the immediate term, I guess. Maybe add something like "became a Taii in YEsomething and was promoted to Shosa upon her assignment to the Imperator." It doesn't need to be a table or anything fancy; promotions and assignments can be explained in prose as part of your history.