Long time lurker, went to Iceland 3 years ago early March, fully prepared for the cold in v expensive and lots of layers £200/300 trousers and jackets, some bought some borrowed, proper thermals, snowboots/ walking boots, hats, ski gloves the lot and it was still beyond cold. The wind on the northern lights tours was like nothing I ever experienced and I've skied a lot. She has no idea and the kids will be miserable and cold. It was the most amazing holiday but doubt she's researched the best way to do things and certainly not how to dress !