She lives with me and my husband. I am the full-time care giver because her 2 adult children work full time. My mother-in-law is incontinent, suffers from dementia, anxiety, hearing loss, but she can still walk with a quad cane. I have to provide her all her meals and give her medications. She is very dependent.
Being unable to toilet herself should have been your line in the sand. It will only get worse from here.
I suggest you read this 33 page booklet (which is a free download) which has THE best information ever about managing dementia and what to expect with an elder who's been diagnosed with it. I think your husband should read it too, so both of you know what lies ahead.
Understanding the Dementia Experience, by Jennifer Ghent-Fuller
https://www.smashwords.com/books/view/210580
Jennifer is a nurse who worked for many years as an educator and counsellor for people with dementia and their families, as well as others in caring roles. She addresses the emotional and grief issues in the contexts in which they arise for families living with dementia.
The full copy of her book is available here:
https://www.amazon.com/Thoughtful-Dementia-Care-Understanding-Experience/dp/B09WN439CC/ref=sr_1_2?crid=2E7WWE9X5UFXR&keywords=jennifer+ghent+fuller+books&qid=1657468364&sprefix=jennifer+ghent%2Caps%2C631&sr=8-2
Good luck.
How long has she been with you? Does your husband help on nights and weekends?
My mom lives with us and I have an aide come in 4 days a week for 4 hours. Extra aide if hubby and I are going out for a long time. It's given me back a small part of my life.
Good luck.
Either that or your husband needs to quit his job to look after her as she's his mother.
You already know that she will only continue to get worse so it's best now to get the ball rolling for placement, before you end up being in the statistics where the caregiver dies before the one being cared for.
Taking care of someone with dementia does not get easier. As she declines she will need more and more help. She will go from the quad cane to a walker then a wheelchair. Is your home equipped to handle her with a walker then wheelchair? If you plan on keeping MIL with you making plans to renovate is a good idea.
Or decide now at what point will you no longer be able to care for her safely and have to look for Memory Care for her.
Who is responsible for her? Does your husband have POA for finances and for health decisions? If not does anyone? If not there is the possibility that he may have to obtain Guardianship. You might want to have him schedule some time with an Elder Care Attorney.