Hello everyone! Thanks for the replies and suggestions.
I have found some sort of fix for those who, like myself, play on GeForce Now. What I've done is, since I have an older Asus ROG at home (2015ish), is I installed the game on the older laptop, even though it could barely open it. I downloaded the console mode, low-ed everything in settings so I could enter the game, changed my in-game age with the command, saved and exited. I suppose it could work on a lot of other PCs or laptops, the game doesn't even have to be playable. You just need to load the campaign map, open the console, enter the command, and done.
On re-entering the game via GeForceNow, you obviously won't have the console still available, but the age is fine now. I know this is not a solution in and of itself and is rather troublesome, but for me, it worked in the sense that I don't have to replay 40ish hours. Better to lose 50 mins than 40h, I guess.
On the other hand, my characters seem to be extremely active, I already have 5 children, lol.