Sleeping

How much sleep should a person get?

Q: We hear from scientists and doctors nowadays that adults need 6-9 hrs of sleep and teenagers need at least 9 and so on respectively. We also heard about great Ulama and still in the present time who only sleep a couple of hours.

My question is that does Islam have a stance on sleep and do you think we should follow this research?

Adult daughter sleeping in the same room with parents

Q: Is it ok to put my daughter's bed in my own big master bedroom as there is no physical relation between me and my husband due to perpertual illness of him. My daughter is an adult but still childish and since I have heard stories in my own family of jinn coming on my young virgin niece and talking to her as she was left alone in a separate room, I am hesitant to make my daughter sleep alone in another room. She has no siblings. It is only the 3 of us.