I can see how this upsets you. It would me too. You really need to have a serious talk to your husband about his daughter. She is 19 and not a child. He loves his daughter, but this very odd. He needs to stop acting toward her like she's a little girl. This is only hurting her, and not making her to grow up. Tell him that you love your SD, but they need to change their actions a bit. The best thing you can do is be honest with him. Good Luck!