Is this actually an evil campaign? Or are we just convicts?
If the second, is the setting we're coming out of particularly biased against lesbians? Not nessicarily that tribidisim and sodomy are capitol crims, but if a girl was allready pushing legality with a liason--say, a commoner seducing a noblemans' daughter--the judge might be harder on her for it?
It does it gives a +2 bonus (not enough to help her with manacles), but it more importantly can be discharged to allow her (or someone else at her discretion if she implanted it in them) to escape from basically any immediate constraint, it is her only current Mesmerist Trick.
Slip Bonds: While implanted with this trick, the subject gains a +2 circumstance bonus on Escape Artist checks. If the subject becomes grappled, pinned, shackled, or otherwise personally restrained, the mesmerist can trigger the trick and cause the subject to become incorporeal just long enough to slip her bonds (unless they can otherwise restrain an incorporeal creature). This effect doesn’t last long enough for the subject to move through walls or other barriers. If the mesmerist is 12th level, the subject remains incorporeal until the beginning of the mesmerist’s next turn.
So if the guards know exactly what they are dealing with they would likely keep her in a box or ghost touch manacles or somesuch, but there is no real reason for them to know she can do that specific trick (if they even know she is a mesmerist rather than any other random magic user).
General rules for tricks below but highlighting this part for your use:
'The mesmerist monitors for the trick’s triggering condition through a subtle telepathic connection, so he doesn’t need line of sight to trigger it—but anything that blocks telepathic contact prevents him from triggering tricks. An implanted trick lasts until the next time the mesmerist regains his spells' so there is a way to block them being triggered but I am not sure if that even applies to ones that are implanted in oneself.
Technically she can impant and therefore activate 4 a day so she could theoretically free everyone active (subject to conditions above), but she is dubious about them against armed guards (or even if they are just better going to trial and then trying to get out of it, or if freeing potentially dangerous criminals would really benefit her).
A mesmerist can create hypnotic bonds with his allies, implanting magical suggestions in their minds that he can later activate. Each day, he can implant a number of these tricks equal to 1/2 his mesmerist level (minimum 1) plus his Charisma bonus (if any). He can have only one trick implanted at a given time, and implanting a new trick ends the previous one (the mesmerist still loses the use of this ability he spent on the previous trick).
To implant a trick, the mesmerist must take a standard action and either touch a willing creature or implant the trick in himself. A creature can be the subject of only one mesmerist trick at a time. The mesmerist can activate the trick as a free action when a triggering condition is met (as defined in the trick’s description), even if it isn’t his turn. The subject must be within medium range (100 feet + 10 feet per level) for the mesmerist to trigger the trick.
The mesmerist monitors for the trick’s triggering condition through a subtle telepathic connection, so he doesn’t need line of sight to trigger it—but anything that blocks telepathic contact prevents him from triggering tricks. An implanted trick lasts until the next time the mesmerist regains his spells.
Once triggered, a trick is no longer implanted, and can’t be triggered again until the mesmerist implants the trick again. The duration of the effect caused by triggering a trick is either instantaneous or appears in the trick’s entry. The DC for any mesmerist trick or masterful trick that requires a saving throw or skill check is 10 + 1/2 the mesmerist’s level + the mesmerist’s Charisma modifier.
The mesmerist knows one trick at 1st level, and learns another trick at 2nd level and every 2 levels thereafter (to a maximum of 11 tricks at 20th level). Each daily use of mesmerist tricks can be used to implant any trick the mesmerist knows. Unless specifically noted in the mesmerist trick’s description, a mesmerist can’t choose a particular trick more than once.