once again the mindset of all these kids is ridiculous. to not treat an escaping prisoner as such immediately but instead allowing her to participate in your closed-off community, potentially getting some real intel about your group and even allowing a duel to happen which might just cause massive damage to the few mechas they had available, is just crazy. and she could have tried to escape if she could have started the mecha up which they didn't seem to consider at all. and then they bring her to the bank, where, if she had decided to explain the situation to the bank officials, she could have found a means to escape, since banks tend to be neutral ground, and upon realising she's treated as "legally dead", she just accepts it and instantly thinks about offering her body (is how i interpreted that short panel) but instead accepts to work her debt off.
this is one series where kids kill kids and adults without any second thought, so i guess i'm simply expecting too much depth.