The night watch tends to fall on one person without anyone deciding it should. It starts with a single call or a single bad fall, and then the person who lives closest keeps getting up. The problem you are solving is not that you are weak. It is that one person is carrying every trip, and that will wear anyone down.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Notice the signs
You may be carrying the watch alone if you wake before she calls, if you lie awake listening for the bed to creak, or if you check the hall light from your own bed before you sleep. Other signs: you are the only one who knows where her slippers go and which step creaks, you have stopped going out in the evening, your sleep has broken into short pieces, and you dread the hour when she goes to bed.
These signs do not tell you what is wrong with her. They tell you how the watch is being shared, or not shared.
Count the nights you are awake
For one week, write down each night you were up for a trip, the time, and whether anyone else was awake. Write it plainly, without judgment. The list will show you the pattern faster than memory will.
Split the trips, not just the nights
Look at the list and name the trips that could belong to someone else. A sibling who lives across town can take a set night. A neighbor can be the one who answers the phone. Paid night help can cover a shift if the family has agreed to it. Write each person next to the trips and nights they will take.
Teach the route to the second person
Before anyone takes a night, walk the route with them once while it is light. Show them the switch, the step, the bed edge, and the spot where she usually pauses. A person who has walked it once can handle a trip without waking you.
Set one relief night and keep it
Pick one fixed night each week when someone else holds the watch. Put it on the calendar and treat it as a commitment. Then check at the end of the month whether it held. If it did not, change the person or the night, not the idea.
When the signs are about her
If she has new dizziness, new confusion, or falls that do not match her usual pattern, her doctor needs to hear it. This article does not replace that conversation.
What to write down
Write the names of the people who hold each trip and night, the relief night, and the number to call when the watch needs a second person in a hurry. Keep the list where the next person will see it first.