couldn't be raised if her immediate & extended families are still alive, but i suspect it won't matter when Ragnarok comes
Yeah, I don't think Ragnarok counts, exactly. Something tells me Murphy will be there.
And yeah, Murphy will change, but I don't think Valkyries recruit Einherjaren and they lose who they were. If they did, what would be the point of being selective? Just pick good warriors and the job's done.
Decades in the future, Murphy will have had a different perspective, but I think she'll still be Murphy. Kinda like switching jobs, or becoming a parent, or any number of things that alter your outlook, plus time spent. A salesperson moving over to accounting will have different views after a while.
Murph already changed after losing her badge. Instead, she became a warrior and a guardian. Seems like that's pretty much what she can expect from Valhalla, down the line. In the meantime, it's just mead, partying, and training for a while.