Our house is COLD! We don't have central heating, just a little oil filled radiator in each room that all work on timers to stop the house from freezing! Earl has one in his room and it's on permanently at the moment on a thermostat. I make sure that my thermometers (I have one in each room now....as it gets that cold!) always say at least 15 degrees. At night he has a babygrow, a vest, and is swaddled in a cotton sheet with 1 more layer of blanket over him. He sleeps fine and always feels fine to the touch. I suffer really badly with chilblains and mine have flaired up but Earl seems to be fine as I have blankets over him almost constantly at the moment....wish I could have a blanket on constantly. lol I would say that it's probably a bit much to have a hat and mittens on and I would probably lose one of the blankets, but keep checking her as you will be able to adjust with that many layers. AAnd get some thermal socks for your feet as hurting toes are the start of chilblains and you don't want them!!