Aged mother-in-law has declining mental faculties and she is the caregiver for her schizophrenic son, but she can't take care of him. How do I broach the subject when she feels everything is fine?

Is your BIL able to live on his own when his mom passes? I have a similar situation. My mom and brother lived together for years and she passed away 4 years ago. My brother has the same diagnosis but is able to live on his own, pays his bills, and does his own grocery shopping. He is very adverse to doctors however and just refuses to go, making one excuse after another.
I watch over him from 200 miles away and have found him places to live near me (section 8 senior housing) and he is on their waiting list and eventually I plan to move him down here near me.
This is a really difficult situation for your family to deal with. I can't tell my brother anything sensible, he will acknowledge what I suggest but then doesn't follow through. It stresses me out all the time. I have come to the conclusion that I am going to have to wait until something catastrophic happens and then just take control over him. I can plan for his future all I want but if he is not on board, I can't force him. So I just try to be the supportive sister, talk or text him very frequently and hope for the best. I am fortunate in that he recognizes the need to budget but still overspends on stupid stuff he doesn't need. He is fine being alone, and all his neighbors sort of watch out for him. They all have my phone number too.
Dealing with mental illness is very hard.
Good luck to you and kudos to you for planning ahead, as you will need to be aware of the resources available.

Dear Monica,

Good of you to notice this change and try to get some help. Its not easy. No one likes to admit they need help. I'm sure its a scary time for your mother in law and her son. They have relied on each other for so long, I'm sure any change will be traumatic. I hope APS can help get you in contact with the resources needed to support them. Maybe hiring a live in caregiver is an option or more home care at this stage.

I agree. Call APS and get it started. Your MIL needs help for your BIL and perhaps herself as well.

You should also contact NAMI (National Association of Mental Illness) if you haven't already done so. Where we live, there are group homes and apartments for people living with a severe SMI (Serious Mental Illness) who are destitute; transporation for daily appointment or errands is provided for (buy the State); drop-in centers where are there is socialization and activities for these individuals to participate in. These individuals are also automatically enrolled into the State's Medicaid System. Talking to NAMI now regarding your BIL situation will give you time to get him set-up in the event your MIL needs to go into an assisted living facility/nursing home. You can also contact your State's Human and Health Services Department to see if someone can give you ideas about your MIL.

Thank you for your suggestion. I had no idea where to start, but when I look up Adult Protective Services it seems as though it is geared toward "older adults or an adult with disabilities that are possibly being exploited, abused or neglected." (NC DHHS) so I don't know if that is the right fit. I will contact them anyway, because if they are not the exact people I need then maybe they will know who is.

At this point, I think Adult Protective Services (APS) needs to be called in to make suggestions as to the care for both of them, since they are both adults. It's not going to be an easy conversation, but hopefully the social workers at APS can help you make some decisions and make some suggestions that might make it easier. Your mother-in-law doesn't need to know that you called them at this point - just have your husband call and explain the situation and ask what should be done to help them. There may be an opportunity for in-home assistance or something to that effect.