She is a traveling fortune teller, and like many who ply that trade, her true skill is the observation of subtle clues in her marks, the use of seemingly innocent questions and basically telling people what they wish to hear.
Her own fortunes have not been great, for while she necessarily maintains sobriety while working, her extracurricular drinking leads to exceedingly adventurous but poor decision making.
Originally she was simply a vagabond alcoholic who used her feminine charms to get what she needed to survive. On more than one occasion (none of which she actually remembers) she provided a prophecy while flirting that was striking enough to remembered, and also came true.
Around the same time, after repeatedly wasting every swindled penny she had, a plan came to mind. The next time she had a good win from a gullible man, she would lock her self in her inn room to avoid any temptations. She told the innkeeper that she was a werewolf (seeing as it happened to be full moon) and for his own safety he should lock her away for the night.
And so she transformed from a lush swindler to a sober clairvoyant who was rumoured to be a howling beast once each month. And on that night each month she would be ceremoniously locked away, with some flagons of wine to reward herself.
