Well I don't buy it, sounds like a ridiculous excuse to not portray her how she is supposed to look. She died 3 times not just once, if she died just once I could somehow understand that she found a way to perserve herself. But no, she was stabbed, and her body was left to rott before she found it, then she fell on Saronite spikes, and then got headshot. In LTT's short story she was described as hideaus and thar she smells.
But now we got this asspull that Valkyr are kinda working as beauty salon, that can provide better regeneration than trolls have. Also, why the ook undead would care how they look anymore, they're dead.