Oh, it's been so long and still not upto the anime so I thought the manga had been axed.
(the official raw also blocks access from outside of the country so couldn't even check)
its been 300 years since her pal the Adandara appeared. i miss them i do wonder what that sparkle on the slime was. Sora sparkled early in series too, but that thread didnt lead anywhere (unless it did, and it just wasnt clear)
She was/is, they didn't figure out her disguise, and her being a boy in their view was not a negative. I'm pretty sure she told the adventurers she trusts at one point.
I'm pretty sure there would be buyer segment that would be interesting in young boy sex slaves. So I don't think it would matter what gender Ivy ends being if she was kidnapped and sold. The criminal organization would just offer her as a product to a different set of buyers.
Later in the story, we can deduce that the slaves is not just relegated to the sexual stuffs, Its actually related to the main antagonist of the story where everyone is trying to remove. There is a reason why they chose young boys for this though I'm not gonna spoil much.