The girl in question is located, when she is located, at the docks, setting fire (at a distance, via a burning string) to a horrible-smelling concoction, which produces sputters. It took some difficulty to recognize her from her picture, since she's wearing a welding mask made from the corpse of a steel washbin and leather armor of sewn-together squares for PPE.

"Who wants to know?"

(Casual glance left, casual glance right; where's her gang? Not here. Can she take him? Probably not.)

"I am a member of King Ben's royal guard and I have a message for your father, if you can take me to him."

... Her father? Nobody cares about her father!

"Like I know where he is."

He sighs. First Cangse Sanren was dead, then Tetley had no idea who her parents were at all, and now this. "--Well, then, I guess I have a message for you." He adjusts himself and attempts to sound regal. "By orders of King Ben, all people on the Isle of the Lost who have not themselves committed a crime will be set free and allowed to live in Auradon. We are beginning with a pilot program of four teenagers. You have been selected as one of the members of the pilot program."

And that is, perhaps, where Alida freezes.

When she was six Alida had decided not to die. They had decided she would suffer, they had condemned her - a powerless child, scrapping in the gutter for what would let her survive - she had sworn to live, to spite them, and she would be free, and one day she would have her revenge.

And now they were letting her go. Just... letting her go.

"Bullshit!" she says.

She's going to blast her way out of her - they're letting her go - what is Uma going to say -

He knows that teenagers on the Isle swear. It isn't, objectively speaking, any worse than the pickpocketing and the face-spitting he knew they were doing. It's just-- not the sort of thing you talk about in front of children, so it's not in books or on the television, so he didn't think-- but of course they swear.

He still can't stop himself from flinching. 

"If you and your father agree, you can meet at"-- he gives directions, much more confusedly than any Islander would give the directions, to a place squarely in Mal's territory-- tomorrow at 6pm. That's, uh, about the beginning of sunset."

... "And I should believe you, random fancy costume man, because..."

Is she going to need to find her father? Nah, if he doesn't believe in swearing, and he is this much of a rube, she can just tell him Gustav approved it, it's not like he wants to be here.

"I am a person you don't recognize when you certainly know everyone on the Isle by sight, in clothes that no one on the Isle wears, and no one can break through the magic barrier without King Ben's approval?"

"... Yes, and King Ben gives a shit because... look, 'organ shortage' is way more likely than conscience where I'm from, all right?"

(Actually, she's really just saying this for the chance to watch his facial expression; he is an amazingly bad liar for someone who survived to his age.)

Horrified: "We're not going to murder you! Only evil people do that!"

Holy shit how did Uma's mom not just conquer the world, they're like babies, seriously why.

"Riiiiight. Uh-huh. Sure."

"Do you have any pointers to where I might find your father?"

"Sure." She can give him a pointer, which will almost certainly be useless because it is directions to 'where people from regions vaguely near where her parents came from settled', but it's not like that will be relevant - she has no idea if her father is even alive, and that's the way she likes it.

And then she can go talk to the people who have the best of all possible reasons to want to keep her alive, self-interest, or at least who did yesterday.

Uma, Harry, and Gil, along with their lesser minions, are at Ursula's Restaurant as always. 

"Hey, boss!" Alida says, waving. "It turns out that we were never supposed to be on Garbage Island in the first place, and if four Islanders manage to get along with the assholes who sent us here to die everyone born here can go wherever the hell they please!"

"I heard it from Tetley," Uma said. 

"And she's totally mad that that little garbage-picker got picked instead of her," Gil adds, "even though it makes sense that they're going with someone weak and wimpy who isn't going to challenge them and not Uma. If she'd known this was going to happen then she wouldn't have founded a gang!"

Harry hits him in the head. 

"So, the two main questions are, one, is it a trap, and two, if it is not a trap, can Tetley, me, and whatever other two children of henchmen they choose play along for long enough to get them to release everyone else?" At which point they will have magic and books and be in a much better position to plan vengeance.

"Obviously it's a trap," Uma says. "The question is whether you can get the cheese without becoming dinner yourself."

"... The guy I talked to was really dumb," she says, which is both an observation relevant to the question of her odds and involves some suggestion that he might have trouble lying to her. "No idea about his boss, though."

"King Ben grew up in prissy rich-kid Auradon," Uma said, "how clever can he be?"

"Ben, I'm not worried about, but someone's got to be pulling the strings. We can't be the only people who want to be in charge." There's going to be intelligent opposition somewhere; someone in Auradon has to want power and be good enough at getting it not to be shipped to Garbage Island.

"But they're going to think we're stupid," Uma says, "because all the teenagers they interact with are stupid. --What I want to know is why they picked you. Tetley, I understand. No one is threatened by Tetley."

Good point. "I think they picked four henchkids, and didn't know or care who they were, because they think teenagers are too dumb to be a threat. Tetley's them getting lucky." And I'm not.

"That means that Uma is mad that you got picked and she didn't!" Gil added. "Ow!"

"I sent someone to get information about who else was picked," Uma said, "and we'll be able to figure out something from that."

"Even they can't be stupid enough to think you aren't a threat," Alida says, nodding in respectful acknowledgement of Uma's plan. "But we'll still all be off this rock soon enough, one way or the other."