MIL doesn't sleep at night without someone there. Any advice?

No, I have not experienced this kind of behavior, but I would get her a weighted blanket and a life size baby doll that feels like a real baby.

My granny did so much better holding her baby all the time.

We even bought it outfits and in her world being a mommy again kept her very contented and loving.

BBC Radio 4 here in the United Kingdom has a regular programme on Wednesday afternoon (United Kingdom time with US East Coast five hours later, Midwest 6 hours later, Pacific Coast 9 hours later) called “All in the Mind” with Claudia Hammond, for Wednesday afternoon 19 June titled "Sleep and Dementia." Just search Google after that date for Radio 4 Schedule and you will find it, either to listen live or listen later.

My wife, with Alzheimer 's still lives at home with me in the 57th year of our marriage. She is confined to a hospital bed, but I put up a comfortable bed frame and mattress and sleep beside her each night. She told one of the carers that this was "lovely." I find that she needs this reassurance that there is someone close by; and we both get a good night's sleep.

The amount of sleep any of us need is also linked to how much activity we have during the day. You might find helpful Dr Rangan Chatterjee's "The 4 Pillar Plan: How to Relax, Eat, Move, Sleep Your Way to a Longer, Healthier Life." You need to work out a balance between these four aspects of life--relax, eat, move and sleep. This is just as true for someone with dementia (and their carers) as it is for anyone else. There is no single answer--trial and error, experimentation, asking for advice, finding suitable prescriptions--are all part of the answer.

With my best wishes and prayers

I have had to sleep with my momma for the past 9 months. She is scared being alone and if I am there I can calm her down and keep her in bed so we both get a good nights sleep on most nights.

My mother with vascular dementia wants my dad in bed with her... she grew up sharing a bed with multiple siblings and needs the comfort of a body next to her.
Have you considered a small group home type facility? There are fewer residents and may feel more comforting to her than a large facility.
Large facilities may have a revolving door of night caregivers...one per floor. It is scary to wake up to a stranger at night.
I would try a camera in the room just to see what her nighttime needs are. Then try to build a care program from those needs.
Ggood luck! This is a tough one.

Is she on any sleep aids? Anti-anxiety meds? Seems like she needs something to get her through the night, for her own good, as she certainly could benefit from some rest!

One 90-year old man I knew who was well into dementia but could be lucid at times, and who begged me to get in bed with him ("Nothing will happen") because as he said, "I was married for more than 65 years and I miss sleeping with someone." If I just sat in the chair in his room, he seemed fine. Maybe your mom missed another body, if not in bed at least nearby. Maybe she's becoming afraid of sleep (which some people do as they near death). Would music help her?

At her stage, can’t they give her a sedative to knock her out in the evening.

Just a thought, but maybe giving her a baby doll or stuffed animal to sleep with might give her some comfort. I've seen women carrying baby dolls with them in the nursing home & it seems to bring them comfort.

The first time I was on my own, I slept with a lot of pillows all around me, I had one of those long body length ones and just being cocooned helped me a lot. I don't know about it now that I am old, I have to go to the bathroom at least 2 times a night and they might make it harder to get out of bed. Perhaps someone else who is experienced in this can help. ((HUGS)) you need them. Oh, is her mattress comfortable for her? I know I have had to go to a very soft memory foam because of aches and pains with my old mattress.

My SIL with Alzheimer's doesn't want her husband to leave, but he has to - to go to work. Get her a stuffed animal or perhaps moreso a baby doll to sleep with.