The so-called ill-intentioned adventurers had the flimsiest fucking plan/composure I've ever seen. Oh, an old man in adventurer's gear states aloud that she won't be able to get any work unless she officially registers for everyone, including the girl you're trying to trick, to hear.
Your response? "Shut up and stay out of this old man". No brushing it off with "ah, we almost forgot", "we're just taking her to a more secure place for an interview to see if our intuition about her compatibility with our party is right", "We want to test her capabilities real quick", nothing.
Just an immediate awkward response of "stay out of this". As long as anybody isn't brain dead, no one is going to follow you after that retarded response.