What Causes Swelling All Over The Body After Delivery?

my daughter is having swelling all over her body (hands, arms, feet, knees, thighs) 3 days after delivery, her BP is normal, no headache or fever or pain anywhere. It was a normal pregnancy and delivery with an epideral. She also has a scarlatina rash all over, which she gets when she has a virus., and has a sore , red throat.