A carpet-to-hard-floor seam on the night route is a small thing that causes large falls. Where the carpet in the bedroom meets the hard floor in the hall, the edge can be raised, frayed, or a slightly different height from the floor beside it. In the dark, she may not see it. Whether you fix it yourself or call a flooring person depends on what the seam is doing, not on how handy you are.
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.
Check the seam first
Look at it at night with the light she uses on the route, and then again in daylight. Run your hand flat across the edge. Lay a straight board or a ruler across the seam and see whether one side stands above the other, and by how much. Press on the edge to see whether it lifts, shifts, or makes a sound. Write down what you find in a short list, with the height you measured and where on the route the seam sits.
What you can do yourself
If the seam is flat, sound, and only needs a finished edge, a transition strip made for that purpose may be a homeowner job. Read the package for the floor types it is made for, and test the fit dry before you commit to it. Once it is down, walk it at her pace with the light off and then on. If she catches a toe on it, or the strip lifts, stop and take the job off your list.
When to bring in a flooring person
Call a flooring installer when the height difference is more than a small step, when the floor under the seam is soft or moves, when the carpet edge is frayed or pulled, or when the fix would mean cutting the existing floor. Those are not weekend jobs. Ask whether they will remove the old edge, check the subfloor underneath, and leave a finished seam flush enough that she can walk it in the dark. Ask them to show you the finished edge and to walk it with you before they leave.
Questions to ask before you choose
Ask who will do the work, whether the company carries the job from start to finish or passes part of it to someone else, and how they handle a problem they find under the floor. Ask what the finished edge will look like in both daylight and dark. For trades that take this kind of work, the local help after a fall page is a starting point for St. Louis.