Answer:
Violet, Peony, "Mamma", and snow sister.
Violet and Peony are the most major characters, as they are why our focus is given to mamma and why snow sister is made. Mamma is only elicited our attention when she is giving a reaction to the children's actions; and our focus is somewhat shifted to her throughout the story. Snow sister is a major player because of the effect she causes on the characters, especially mamma.
Hopes this helps ^^
