You mentioned Alex was born 9 months after reaper war, so are you headcanoning Ash was pregnant already by the ending of ME3?
Hi nonny, thanks for asking.
So Ashley actually got pregnant around the night before they hit Cronos Station (so basically at that romance scene or maybe some time before in the "behind the scenes", cause why not? Oops) and take down the Illusive Man. (Now this wasn't intentional on their part, but by the end of the reaper war (this is my take it on it, of course) it was probably difficult to take a hold of any contraception's at that point. With everyone on limited supplies and such. )
Nine months after Alex was born.
John had already re-taken command of the Normandy by that time. I headcannon that his cybernetics did not get affected, and he still heals rapidly so it didn't take him long to get cleared so other people could get the care and attention they needed from the limited medical staff available.
Ashley at some point was exposed to eezo and by extension Alex was as well.
Alex was suppose to be born at home, but last minute circumstances prevented the Normandy from docking at the Citadel and thus Alex was born on the SR-2 making her of spacer background. She definitely loves to say: "I was born in space".
I needed John still young enough to fight alongside his daughter for her main story that I will be working on at some point. Thatâs why I put her down as born nine months post-reaper war.