My short answer is YES, I think you are right that she needs more care.
It is not okay for her to be locked in her house. If there were a fire, she would not be able to get out and could be seriously injured or die. Could her son live with having caused that?
If she is not safe to be left alone, then she either needs 24/7 live-in carers, or she needs to be in a care home/residential facility.
To temper the bluntness of what I've written above, let me tell you my own story.
My mother is 73 and until January, lived alone with no services, 100 miles away from me. She has had a string of minor health issues over the past couple of years and I knew something was wrong, but didn't know it was dementia. I am an only child, as is she, and she had no family in the area who could help (one cousin who is elderly and infirm; my parents divorced when I was young and my father is dead).
Early one morning in January, I got a call from a neighbor. My mother had been found, wandering, disoriented and distressed, no coat, very cold, and had fallen (black eye, bruises). A Good Samaritan just happened to find her and to knock on the nearest door, who just happened to be a neighbor whom I know, and who called me. My mother was taken to the ER/A&E department, assessed, and transferred to another facility where she spent about 2 weeks under section/in a locked ward/in the Geriatric Psych ward. She was determined to not have capacity and to need 24/7 residential care and is now in a care home/facility/assisted living here in the town where I live.
My mother will tell you she loved living alone, was very happy, and that everything was fine. She had lots of friends and was very busy all the time. She played bridge every Wednesday night and saw friends regularly, Jane on Thursday and Mary on Friday and so forth.
The truth is, my mother could no longer drive safely but was still driving (a nightmare accident waiting to happen). She was a smoker and I lived in fear she would start a fire and injure/kill herself or others in her building. She could no longer do her shopping or cook a meal. She lost a great deal of weight and was living on ice cream and coffee and biscuits. She was not able to clean, do laundry, or wash herself. Her home was filthy, unsafe, and knee-deep in clutter/garbage. She could barely pay the bills. She threw away all her mail, as she couldn't cope with it (for the last several years). She had started giving money over the phone and in person to scammer "charities," to the tune of over three thousand US dollars. She couldn't sleep. She was anxious and upset all the time. She had no friends and very little social contact. She hadn't been to bridge club in months, and when she did go, couldn't play. She had stopped her regular Friday night visits with Mary over a year and a half ago. She could not take her medications properly and was regularly over-or-under dosing herself. She refused to go to the eye doctor (last visit was 2009) despite barely being able to see. The list goes on, but she was "fine!"
After six months in the care home, where her medications are monitored closely and given to her properly and she is offered three nutritious meals a day, she is eating and sleeping regularly and has regained the weight she lost. Her hair and skin look much better. She no longer smokes and her cough has disappeared. Laundry and cleaning are done for her and I take care of all the mail and bills and financial things. She has no more anxiety about what she is "supposed to do" but cannot do, and her anxiety is gone. She has friends at the care home and people to talk to whenever she wants. She is taken out to lunch at least once a week. There are activities planned, or she can be alone in her room if she prefers (but the staff tell me she is never alone in her room except at night, always in the common areas, talking to people). There is someone to make her a cup of coffee whenever she wants it.
If I had known she had dementia, and how bad it really was, I would have moved her into a care home much sooner. She was really suffering and anxious and distraught living on her own, and that is all gone now. I don't know if she is happy or if she can be happy, but she is safe and more than content. Care homes are not necessarily a bad thing, although never an easy decision. I had the decision taken out of my hands, and it was precipitated by a crisis, but waiting for the crisis was excruciating and also I was remiss in making sure my mother was safe and that others were safe from her. That part still haun
So that is just one story, about one situation, but perhaps it will provide some perspective for you.
I hope you are able to find a solution for your MIL.
