I just put my Mom (84) in a nursing home today. How to you convince her that the nursing home is her home?

She has moderate dementia. My mom has significant cognitive decline and can't live by herself anymore, She used to go to Adult Day Services 5 days a week, but it is not enough. I am her primary caregiver and I am also getting a total knee replacement in one week. My mom that she was going home with me, so I had to leave without telling her. I told the nurse to look out after so that she finds her room. I am afraid when I visit her again, that she wants to go home with me. Should I give her a day or two to see her? I felt terrible leaving her without telling her, but she doesn't understand that the nursing home is her new home. She also has a roommate, and her roommate has over half the room. My mom's side is very small and only has room for her bed a nightstand. Her roommate has a recliner on her side, and there isn't room on my mom's side for a chair. What can I do about getting her a bigger room?