I need suggestions. Help

Since she needs to be mobile in the house free of alarms, and the only real problem is the exterior doors, what about a deadbolt up high, out of her reach? If it’s only a problem while you’re in the house (as opposed to when you go out shopping or whatnot), you could even use a latch that will keep the door shut if she tries to open it.

In reading Midkid's reply, I did remember baby doorknob covers. It has to be a round knob. The covers are plastic and fit over the knob. For Mom they just go around and around. Only you know how to use them correctly.

And the baby gate, mine came with an accessory that allows it to be used as a gate, installing it to the door frame.

I would have a siren installed close enough to where you sleep to wake you up if the alarm is set off.

The whole idea of home alarms is to not be caught sleeping by an intruder. You now know that you could be caught sound asleep in your bed.

This will awaken you if anyone breaches a door or window.

Deadbolt and either unplug the garage door or find a way to disable it. We had to do both with my mother for a while. Inconvenient but necessary.

Deadbolt and either unplug the garage door or find a way to disable it. We had to do both with my mother for a while. Inconvenient but necessary.

Well, this is a big wake up call that tells you that current plan is no adequate to protect Mom. I am afraid when you say "Putting her in AL is out of the question" you rather have kind of closed the door on us. I honestly cannot imagine that placement will not be the ultimate the ultimate solution. Things are so unlikely to get better where the wandering is concerned. It will begin to happen during the day when Mom is not right at your side.
I agree that locking her into her bedroom would not be safe. That would be my worry with gates and locks as well. I just am paranoid about fires. And as I said I fear Mom may begin to wander farther during other times of the day. I think that Cashew's idea is a good one, about Mom being able to get no farther than the yard, but don't know weather conditions where you live, and if cold or too hot that could be far enough to cause damage, and certainly a lot of worry.
I wonder if you could simply CLOSE her bedroom door, and install some sort of trip alarm that goes off at your bedside when it is opened. That would be assuming she has her own bathroom for those frequent bathroom trips. You might speak with an alarm company and explain your exact situation.
Afraid that's the best I can come up with and surely do hope others have experience with this and good suggestions. Wishing you the best.

I use confounding locks on the doors to the outside (except to the back yard) and the basement. on the gates for the back yard, I have child security locks that she cannot figure out but any one who needs to get back there can open.

So, if she gets out, it just to the back yard.

Just as I was thinking 'baby gate' JoAnn was typing it!

Just make sure that it's set up too high for her to get over--b/c having tripped over a baby gate more than once...we just decided to teach the babies to go downstairs, it was so dangerous to the adults! But one set up a foot or two in the doorway would probably give mom the impression she's up against a door.

Warning: unless you install this really tightly in the doorway, it can be pushed over.
Don't 'go cheap' on this. Make sure that the gate fits VERY snugly in the doorway.

We used to always have the deadbolts with the key in them. I had small kids and sure didn't want wanderers. I think a lot of us have had to resort to these 'fire code' violations for the safety of our LO's who are too old or too young to understand that they're less safe out wandering the streets.

Have you put a baby monitor in her room? The receiver is next to your bed. All you have to do is look at it during the night to see if mom is on the prowl. It's completely innocuous and was a great thing for my grands--I often babysat late at night and b/c of the monitor, I never actually 'saw' my grand in person. Just a sleeping baby.

I wish you luck--that must have been a horrible way to be awakened!

https://www.alzheimerslab.com/door-locks-for-dementia-patients/

This is what we installed. You can unlock it from either the inside or outside of door.

You cannot lock her in her room. Its against fire code. I used a baby gate positioned high so Mom could not climb over it. She never tried to take it down. Try a dark throw rug in front of her door going out. They think its a hole and won't go over it. Combine it with a baby gate.

If Mom is never left alone, then you may want to put a key deadlock on the inside of the door. Yes, against fire code. My cousin did this because my Uncle kept trying to get out. He was never alone. As soon as he passed, my cousin took them out.

Thank you all for your suggestions.
she does have a bathroom in her bedroom. The gate might work. I’ll need to make sure she doesn’t have anything in her room she would be able to use as a way to climb over it.
You all are lifesavers when it comes to a sounding board!

Can you put up some sort of gate system (like baby or pet gates only taller) so that she is contained to accessing only a few rooms and not any exterior doors? Have you tried a commode in her room so she doesn't have a reason to leave the room during the night?

Depending on how "active" she is during the day and how much napping she does, you might want to give her activities like kitchen towel folding (like a lot of them) or sorting objects. These tasks help them to burn mental and physical energy and may help her sleep through the night. It helped my 99-yr old aunt a lot, and she was taken off the Tylenol PM that the family caregiver was giving her (plus it was making her constipated). If nothing else works I would approach her doctor to discuss possible sleeping meds so that both of you can get enough rest.

Take a look at your floor plan of your house.
Is there a hallway leading to the bedrooms that include the bathroom, your bedroom, and Mom's bedroom?

Install a door there.

Lock it at night.

You could also install a row of lights leading from her room to yours, to be used as directional signals or reminders of where she might go. That is if you think
she could cognitively do this.

Both you and your Mom must have been scared to see police. Exiting the house through the garage is just what a thief/intruder might do.

Maybe get a consult from your security provider for future reference.

Even though you regard a facility or even home help as "out of the question" and "unaffordable," I suggest you start working with Medicaid right now as to how to accomplish this, for when and not if you need it.