I wish it was just cold conditions she was cold in. She wears a thermal, long sleeve shirt, UA cold gear fleese, jacket liner and then the jacket and is cold in 20 degree weather. It's bad.
Thats why she's cold! she has way too many layers which stops her body heat from circulating. All she needs is a wicking base layer (I prefer merino wool) a long sleeve shirt thats a little looser and an insolated jacket. If she only has a shell for winter then remove the long sleeve shirt and add the fleece. Just make sure to stay away from cotton. I'm a small girl who's always cold as well but I learned that more didn't mean warmer. If she always has a cold butt like I do, I strongly recommend neoprene shorts. There's a thread I started a while ago called the Butt Question
with info on that.
As for the hands...go with mitts but if she's working hard her hands are going to sweat. I always have two pairs of gloves. One for the morning and one for the afternoon. That way if I sweat a lot or wipeout I have a dry pair to finish the day with. There's nothing worse that wet mitts or gloves.