It’s heavily implied that they weren’t actually related to Ike by blood, but their parents would have made it appear so to Poe.

It is an interesting question if an aunt by marriage would get priority in custody if you’ve never even met. I’m actually a lawyer lol but not a family lawyer. Just going off what I remember from the bar, custody would be determined based off the best interests of the child. If goes to a non-blood aunt meant that they remain in a similar cultural setting to what they grew up in, then that might be in favor of her.

However, I forget, is Justice Strauss from the same city they grew up in? The stability of staying in the same city would heavily be in favor of her in that regard. And Violet and Klaus’s opinions would be taken into account.