Give her an aphrodisiac.

A silent treatment was not something you preferred. You grabbed a bottle of wine you had brought with you and slid it through the bars.
"Wouldn't want you dieing on me." You told her.
You had added a strong aphrodisiac to it. Any person who drank from it would get horny after but a few minutes. You just needed her to swallow.
"Drink." You ordered.
Instead, she took the bottle and rolled it back.
"For all I know it could be poisoned. I'm not drinking or eating anything you have to offer."
You looked at the bottle, and knew she was right. What reason did she have to trust you. You were her enemy.

You took hold of the bottle, uncorked it and drank from it. You then put the cork back and rolled it to her again.
"It's safe." You tell her. "If it were poisoned, then I am now as well."
That seemed to have done the trick. She hastily grabbed the bottle and gulped it's contents down her throat.
"Gotcha." You thought to yourself while grinning. Just a couple of minutes, and the results would start showing.