Dear jackdebh,
It is hard in the beginning. Now my father-in-law is in stage 6 with Alzheimer's, and at times he still says he would like to walk alone or even jog alone (he can no longer jog because he needs a cane and can only walk a long block now.) Sometimes these patients have the illusion that they can do the normal things they used to do. They have no idea they have Alzheimer's. My FIL has never admitted Alzheimer's whatsoever and now he is too sick to understand even dementia. Back in 2005, he was very stubborn not wanting to have any caregiver with him as he lives alone. Like your mother-in-law, he didn't want to pay the money (was cheap at that time as it was part-time; now it is 24 hours.)
We learned it the hard way. In Oct, 2005, the neighbor came over as we requested and said he was sick after he fell one time at the stairway, and his medication was too much so he was too sleepy and confused. They forced my husband to go there right away or they said they would call the social worker.
So my husband flew there with expensive airfare the next day and immediately found this home care service to have someone come over to see him one hour a day. We told my father-in-law it is the law and that he has to have someone. Later on in Oct. 2007, he got sicker and could not walk a long distance anymore. The caregivers told him he cannot be alone and got someone 24 hours overnight. The first night, my FIL called my husband and blamed him to get this overnight caregiver who "scared" him the first night as she was asleep downstairs at that time. In any case, the home care people managed to let him get used to the 24 hours care. He forgot at times and he didn't realize the girl was in the other room in the front and he stays in the back downstairs now so sometimes he has no idea at all.
It is true at times they don't admit they cannot be alone. At times, my FIL now says he cannot be alone but he likes to walk out alone and etc.
You probably need to tell your mother-in-law that you need to find someone to be with her or the neighbor will be angry. You see, when she is alone, she can wander to the neighbor's and complain!! The neighbors can be nice or mean and they will tell you that you need to get someone to be with her! Just tell her that the social worker says you need to get someone. Get some legal reason so she must accept it.
You can also get the person first and try it so she will get used to it. Later, she will stop asking. You can just say you hire this person for yourself. She may feel shameful if the person is for her. You could use some excuses like the person is working for your house and etc. So she can feel better.
Just my experiences.
Take care,
Nina