M.E.
My son was the same way when we brought him home from the hospital. It took him about a week and a half to get it figured out, now he's four and a half weeks old and he stays awake during the day hours and sleeps his long stretches at night. Just make sure while your daughter is sleeping during the day try to nap with her, if you can I know you have 2 other children which might make it more difficult. I know it's hard, but that's what got me through it.