Molly met Prince Charming one day while working. He was eating alone at Gottfried's and she was his waitress. The two began flirting and by the end of the meal, Molly was ready to ask him back to her apartment as she was soon getting off work. At this point Charming revealed he was actually broke and could not afford the meal, so she agreed to pay for him (as she would have been stuck with the check if he'd skipped out anyway). The two returned to Molly's apartment and had a night of very passionate (and apparently very loud) sex. The following morning, while Molly was still sleeping, Charming took the spare key to the apartment and some money, and went to collect his things so that he could move in with her, leaving her a note asking her to do his laundry.
Molly was merely another of Prince Charming's conquests, to be taken advantage of and then cast aside, although he did refer to one of his later conquests as "Molly" accidentally.
Much, much later, Molly was turned into one of Mister Dark's witherlings.