She follows you because you are her person, and a geriatric cat who still wants to be where you are is showing you something worth protecting. The aim is not to train her out of the stairs or to carry her against her will. The aim is to remove every penalty attached to the trip, so that being upstairs or downstairs costs her nothing beyond the climb itself, and the climb is made as kind as a staircase can be made.
Duplicate Her Whole Life on Both Floors
Set up a complete second station upstairs: her food served there when she is up with you, a water bowl placed away from the food, a litter tray with one low side she can step over without lifting stiff legs high, and a bed with supportive padding in a warm, draught-free corner. Downstairs keeps its own full set, unchanged and familiar. Duplication changes the meaning of the stairs for her. She no longer has to descend because she is hungry, thirsty or caught short; she travels when she wants company and rests where she lands. Keep the upstairs tray scooped as faithfully as the downstairs one, because a dirty tray teaches her that the long trip down was necessary after all.
Make the Stairs Safer Rather Than Forbidden
Bare wood and worn carpet are hard on ageing paws that grip less surely than they once did. A fitted runner or grip strips on each tread give her claws and pads something to hold, and a handrail-height light or a low night light lets her judge each step on trips in the dark. Clear the steps completely and keep them clear: shoes, post and laundry baskets turn a manageable climb into an obstacle course. Where the staircase turns or runs long, a small landing bed or a wide, stable pause point lets her rest midway without blocking the way. If she bunny-hops with both back legs together, pauses longer than she used to, or cries partway up, treat that as information about pain or mobility and raise it with her vet, who can assess what is changing and discuss what may help her.
Let Her Choose, and Keep Both Floors Worth Choosing
Duplicated stations only help if they stay complete, so fold them into your own routine: refresh the upstairs water when you go up to bed, check the upstairs tray on your morning trip down, and wash both sets of bowls together so neither station quietly degrades into a second-class version. A geriatric cat notices neglect quickly, and a stale upstairs station teaches her that everything worth having is still downstairs, which puts the burden straight back onto the stairs you were trying to make optional for her.
Resist picking her up for every trip unless she asks in her own way, because being carried removes the gentle exercise and independence the climb still gives her. Walk at her pace when she follows, rather than hurrying her, and spend unhurried time with her on whichever floor she has chosen so neither level feels like exile. On days when she seems stiffer, bring your evening downstairs to her instead of expecting the climb. Keep a brief note of how she manages the stairs across the weeks, alongside her appetite and weight, because a slow drift is hard to see day to day. Those notes belong with her health records in KinsLe, where Pet Passport gathers them into one portable set that a locum vet or a boarding carer can read at a glance.