The closet rod is the job that gets done halfway. It was hung high because that is where it always was, the hangers stop above her reach, and the coat she wants ends up on the floor. Lowering it is a small install, and it goes in the right order only if you start by measuring what she can reach, not what the closet holds.
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.
Measure her reach before you measure the wall
Have her stand or sit in the spot she usually uses when she dresses. Ask her to reach for a hanger the way she would on an ordinary morning, and mark with painter's tape where her hand comes to rest on the wall. That mark is the height the rod should sit at, with a little room for her hand to slide hangers on and off. Check that the spot still leaves clear floor for her walker or chair in front of the closet without bumping the door frame.
What makes this hold: the rod sits where her hand already goes, not where it looked best when the house was first set up. When it becomes a question for the care team: if her reach changes from one month to the next, or if she has started holding the door frame or the rod to pull herself up, bring that to the care team before you move anything.
Find the studs and decide what the rod carries
Run a stud finder along the back wall and mark each stud with tape. Brackets that land in studs hold a full load. Brackets that land only in drywall need anchors rated for the weight, and in an older house the plaster may be softer than it looks. Decide what will hang on it. Light shirts and dresses can ride on one rod. Heavy coats and stacked blankets need a second bracket or a shorter span, because a rod built for a light load will sag under a full one.
Order the parts against the list
Order brackets rated for the load, a rod cut to the opening with a little overhang at each end, end caps, and screws sized for stud wood. Check the bag against the list before you start. Keep the receipt and the packing slip with the manufacturer sheet, and find out whether the store takes returns on opened hardware. A missing screw size costs a second trip, and second trips are how this job stretches out over weeks.
Set the brackets level, then the rod
Hold each bracket to its mark with a level and check it both ways before you drive a screw. Pre-drill into the studs so the wood does not split, then drive the screws until the bracket sits flat without rocking. Seat the rod in the brackets and tighten or snap on the end caps. If a bracket shows a gap or a screw spins without biting, stop. Back the screw out and move to a new spot in the stud. Do not keep tightening a screw that has lost its grip.
Test it under the load it will carry
Hang the clothes she actually wears, then press down on the middle of the rod with a steady hand. Watch the brackets for movement and the rod for any slip out of its seat. Open and close the door with the rod loaded, and check that hangers slide without catching on an end cap. Then ask her to reach for a garment from her usual spot. If the height is right, her hand reaches the hanger without lifting her shoulder or leaning into the frame.
Check it tight after the first month
Once a month, look at the brackets and screw heads. Tap each bracket with a fingertip and feel for play. Check that the rod has not dropped at one end. If a bracket has pulled loose, take the clothes off the rod before you touch it, and do not add weight until the bracket is back in a stud.
The closet rod is a small job, but it tells you whether the house is set up for how she lives now. If her reach keeps changing, the rod is only the first question. Bring it to the care team, and see local help for keeping her home for who to call when the job grows past a weekend.