The story is based in Switzerland or Norway (I remember mountains). Two children live with their mother high up on the mountain. They are poor - but get by until the mother takes ill one summer / fall. The children remember one Christmas going down the mountain to the village and singing carols in the village with their mother - and being given food and money. They decide to try to do that again to help their mother. When the children walk into the hotel and start singing Christmas carols - the guests, who turn out to be doctors, are quite surprised. The story ends with the young doctors (Americans?) taking the children back to their mother - diagnosing her health and finding a way for her to earn more money to provide for her and the children by sewing mittens, and sweaters "on order" - starting with them!

Can anyone tell me the name of the story and / or author? I'd love to find a copy of this story also.