Not Diamonds and Toads. Not Frau Holle. Not The Twelve Months. Not St. Joseph In the Forest. Has recognizable traits from all of them, of course, since they are all the same time, and some closer than others, but not any given one.
of course, "the kind and unkind girls" allows for a lot more variation than most. Doesn't have to be girls. Doesn't have to be boys, either. Widows with children are perfectly commonplace, or a married couple, or any other twosome can pull it off. And the situations they land it and what gets asked vary a lot. Sometimes they get hired and have to work for months or a year. Sometimes they just have to help someone at the well. Indeed, in the variants where they meet up with the anthropomorphic months, all you have do is be polite, or praise the months each in their turn. And you can put a lot of variation in what the kind and unkind girls get. I naturally set up what they would need later for their fates. . . .
But any tale type has its deep structure. Reading a lot of them will get that structure into your bones, and then when you retell it, you're using your own filigree --
even if that consists of stealing different specific details from a dozen variants.