Re: Alice Krige as.....?
In the animated movie, Hulk vs Thor, they have Hela as Loki's daughter and after reminding them Loki was at least a thousand years old, my nephews had no problem with it.
I saw Jörmungandr on Loki's armor but the photo of what some people claim is Fenrir looked more like a lion to me...
We also shouldn't forget that Sleipnir was in Thor. They didn't address him or his parentage but he was there.
I think Darcy might be easier for most audiences to accept as Hela though...