One gruesome alternative would be to poison their food supply with something slow acting and/or psychoactive. There's chaos, maybe some rioting, lots of people die, we swoop in and slurp her memories along with anything else we want, stab ourselves and make it look like a prisoner did it and then jump to another body in some safehouse. However I don't think Esme would approve of indiscriminate murder.
I don't think we should tell any lies but we shouldn't be too forward either, in case one of those people that can see the past come to investigate. We should say we're working against the state and want her for information. Promise to keep her safe and snuggle her off the country (assuming Esme can arrange for that). If she agrees to that, I think we should just go with breaking her out, along with some other prisoners to make it look like she got out in the chaos of an unrelated prison break. Maybe some of the prisoner names we got are of people belonging to some kind of Mafia-like organization that would be likely to break them out, so by letting them leave we can deflect some suspicion. Then once we get her out safely we can have a normal conversation without risking someone overhearing us. And if things go sideways we can always fall back on the "eat her memories" plan.
What kind of options do we have for breaking someone out? Could we steal a gateway vehicle from someone and get away with it? Or maybe kill a horse and keep it nearby to carry her away? How about explosives, could we use those to break a wall down like they do in westerns?
Finally, in order to avoid communication problems with Esme, could we safely leave a skull or head or something back in the library, in case we ever want to leave but also have a messenger there that can do better than screeching? I'm thinking we give her a small bone hidden in a ring or locket or sock or something like that that can be on her at all times and vibrate to let her know we want to call, maybe even give her some information about the reason we're calling depending on how it moves. Then depending on circumstances we either take over the skull and have a face to face conversation or we command it to speak. Maybe two skulls so we can have one for taking over and another for commanding.