Moving to CA. Our daughter is planning to add a room over their 2 car garage. I would like to know where I can get info about what to build?

My wife and I live in a beautiful 3200 sq. foot home in the mts. of CO. We only use the master bedroom and bathroom. I use the kitchen to prepare very easy meals. My wife had an AD diagnosis 5 yrs. ago but was probably showing signs several years before that. She is in stage 5+ of the disease. I plan to take care of her for the rest of her life (I am 81 and in good health, she is 78 and in good health except for the AD). I would like to know what is needed in this apartment that our daughter and son-in-law are going to build. Any specific types of furniture, bathroom aids. Types of toilets, showers, etc. Kitchenette facilities. A/C, fans. Types of beds. I am assuming that the apt. will be basically one large room and that is all we need. Being close to our daughter and assistance will be very helpful. Now we live about an hour away from Boulder or Golden, CO. I have always been very capable of building and preparing construction but now I need more specific advice to confront circumstances that are brand new to my wife and myself. Any advice will be greatly appreciated.

I have done a lot of research myself but we are entering uncharted territory and I would love any voices of experience from people who have been down this road before.

Thank you. Eddie B.