You do not catch it on a bad day. You catch it on an ordinary afternoon when Mom asks whether the kids are coming for dinner, you say yes, and twenty minutes later she asks again in almost the same words. Nobody is in trouble. But that repeat is worth noticing, because small things like it tend to pile up quietly while you are busy running two calendars.
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.
What a repeat looks like
One repeated question is just a question. The pattern to watch for is the same ask coming back within a single visit or a single phone call, the same story told twice in an hour, or a note you left on the counter that gets read and then forgotten by the next time you come in. Look for the repeats that start changing how her day runs, not the ones that make you smile across the dinner table.
Keep a quiet list for a couple of weeks
Use the notes app on your phone or a page in the kitchen notebook. Each time you notice a repeat, write down the time of day, what was asked, and whether she seemed to remember that you had already answered. Leave out your conclusions. Just the facts, in plain words. After a couple of weeks you will either have a few stray moments or a pattern you can point to, and either result is useful.
What to do with the list
Show it to whoever has the most say in her care. That might be her doctor's office, a care team, or a sibling who handles the paperwork. Bring the exact phrases and the times, not your reading of what they mean. Then ask what they want you to watch for next and how they want you to report it. The point is to hand over a clear record, not to diagnose anything yourself.
Where your help fits
You can keep the afternoon steady without any clinical skill. A non-medical helper can sit with her, keep the routine predictable, write the day's plan on a whiteboard, and remind her of plans that are already on the calendar. That is an honest offer for the afternoon window. Anything about her health, her thinking, or her medicine belongs with the care team, the doctor and the pharmacist, and keeping that line clear is what keeps everyone on the same page. If you are looking for local options, the Local Help in St. Louis page is a good place to start.
Do not carry the list alone
Tell the kids' other parent or your sibling what you have been noticing, even when it feels too small to mention. Saying 'I am seeing this and I want help looking at it' is an ordinary thing to say, and it is the kind of sentence that gets the right people involved sooner.