Ok, but do you know what’d save the FO4 story from a forced heterosexual relationship, a possibly unwanted child in your characters life, and that whole “I’m just taking over a preexisting character, up until now I’ve not been in control of my characters story” feeling?
You are Nate and Nora’s neighbor, also chosen to go into 111, a childhood friend of one of them, and Shaun’s godparent. (This doesn’t even have to enforce a religious aspect on your character, only on Nate and Nora and it’s not their story anymore)
You start off at home, alone, with no weird gendered career backstory items in sight. You talk to the Vault Guy. Then you head over to your BFF’s house for dinner, so we learn about them and why you should care. You get to meet Codsworth who clearly considers you one of the family (now you two have a decent dynamic - both “family members” who aren’t really family members). Your bff gives you a present (it’s a Holotape for you to cry about later when you get unfrozen, with them thanking you for being such a great friend and godparent) when the broadcast goes out on TV.
Nate and Nora die in the Vault (either due to Kellogg or the Cryopod malfunction that kills everyone else), or maybe one of them (whoever wasn’t your childhood bff) doesn’t make it to the Vault in time. You get to see Kellog because ALL the cryopods have to de-freeze when they open up the one to get Shaun out of. Add a bit of story wrangling as to why your pod didn’t fail, maybe it was the last one to cut life support as the generators die and the pods are set to open automatically after 200 years.
So you are now on a quest to save your godson, who you are now official guardian of.
THERE. No more pre-established character mess you have to retcon with headcanons. Very little change in the main story arc. Add as much or as little “Family doesn’t always have to mean related by blood” mush as you wish.
*Endgame spoilers under the cut*