The way they're in a vertical line leads me to believe they're where she's scratched herself. My husband and two of my kids have keratosis pilaris (it's very very common), and theirs is bad when it's dry. My husband's are usually pretty even with the skin, but the kids' are raised. I could see them getting bloody very easily. I'd still see a Dr to find our exactly what's going on. Whatever it is is probably exacerbated by the cold dry weather.
Mom to a girl - 5, a boy - 4, and Baby - 21 months