There is no "normal." What's the old line from "The Shadow"? "Who knows what lurks in the (something something)?" So it's not a decision (what we deem) a rational person would make. No doubt--especially if she has the stamina--adopting would have made more "sense"--especially in the many years that led to this. But I don't see this as "insane." Stupid? Maybe.
There is in my universe, FRiend.
And the Shadow's line started, "Who knows what EVIL lurks in the hearts ..."
I think that's quite relevant to this story.