Mother Hulda, or Frau Holle, is possibly the goddess of Hell, a goddess of marriage, and/or goddess of the weather. Prompted by a footnote in my book, I looked up Mother Hulde on Wikipedia:
The legend itself, as it was eventually passed to the Grimm Brothers, originates from oral traditions in Central Germany in what is now known as Hesse. It was told to them by Henriette Dorothea Wild (whom Wilhelm Grimm married in 1825) with more details added in the second edition (1819). It is still common expression in Hesse to say “Hulda is making her bed” when it is snowing, that is, she shakes her bed and out comes snow from heaven!