My Friend Fell Down Wooden Stairs Last Night And Has

My friend fell down wooden stairs last night and has a massive, almost blackish purple bruise from the tailbone to her hip. It is also raised and feels hard, raised and leatherlike to the touch. She has other similar bruises on her shoulder and elbow. Her entire butt on one size is bruised.
She is in pain (as canb e expected from such a fall) , She will not go to an urgent care center or an ER hospital, How can I help and/or does she need immediate professional help?