The house
The Spare Key Has Two Jobs: Decide Who Holds It Before Dusk
A spare key can get the right person inside after dark, and it can also give Mom a way out, so choose who holds it, where it lives, and whether the lock should change first.
A spare key does two jobs at once. It lets the right person walk in when something goes wrong after dark, and it can also hand Mom a way out she does not need. Before you decide where the spare lives, decide who should hold one and whether the lock itself should change.
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.
Count the keys you already have
Start with a plain list. Note every key that opens the front and side doors, the garage, and any gate. Write down who holds each one now: you, Mom, a neighbor, a cleaner, the person who mows. Keys handed out years ago often belong to people who no longer come by. Collect the ones nobody uses, and ask the people who keep the rest whether they still need them.
Decide who needs to get in
Three kinds of people may need a way in: a family member who can reach the house within minutes, a neighbor who can open up while you drive over, and a responder if someone has to call for help. Responders will use the door, a lockbox, or a locksmith, so your job is mostly the first two. Pick one or two neighbors who live close and who will agree, in writing or by text, to answer when called at dusk. A key in a neighbor's pocket is only useful if that neighbor is home.
If you hire an in-home caregiver, read the agreement for whether they may hold a key at all. Some agencies allow it, some do not, and some require the key to be signed out and returned each shift. Ask what happens to the key if the caregiver stops coming.
Choose the lock route
You have two routes. You can keep the current lock and give keys only to the people you named. This takes an afternoon and leaves the old copies in circulation. Or you can ask a locksmith to rekey the exterior locks or add a keypad. This takes longer, but it ends the question of who still holds an old copy.
Before you call a locksmith, ask three things: will they rekey every exterior lock at once, will they give you a written count of the keys cut, and what do they do with the old keys you hand back. Ask whether they can come out after dark if you need them. A keypad code is only as private as the people who know it, so if you choose one, share it only with the people on your list, and change it when one of them leaves the list.
Keep the spare out of Mom's reach
Do not hide a spare under a mat, in a planter, or on a hook beside the door. A person looking for the way out will check those places first. The safer habit is a key with a trusted neighbor. A lockbox can work too, but only if its code is known to the people who need it and kept away from the house. Whatever you choose, check it once a season: is the key still where you think it is, and does the person holding it still live close enough to come?
Write it down before dusk
Put the list on one page: each key, who holds it, the neighbor on call, and the locksmith's number. Keep a copy where you can reach it from the car. This page is the first thing a helper will need, so make it now, not on the evening you need it. For who to call for dementia help in St. Louis, see Lifelines: Dementia Help in St. Louis.