Sister Cosmas isn't the only one crazy about junkfood.
Sister Carmentine became an oblate (a lay/non-religious woman who helps in the order. In her case, as if she were a nun, but without the vows, and, by extension, without being able to move up in the convent) because in addition to do good deedsl, she would also have more discipline to control herself...
It looks like it will take longer.