A dull view is still a window worth fixing
Your cat has chosen that sill for the light, the warmth and the height, not for the scenery. A blank wall a few feet away and a car park below offer almost no movement at cat eye level, so she sits, stares and eventually redirects that unused hunting energy into night calling, over-grooming or pestering you at the kitchen cupboard. The fix is not a bigger window. It is giving this one specific pane something changing to watch and something active to do beside it.
Bring movement to the glass you already have
Start outside the pane if your building allows it. A suction-cup or bracket bird feeder fixed to the glass itself puts finches inches from her nose, safely separated by the pane, and works even when the wider view is concrete. If feeders are not allowed, a window box with grasses and cat-safe flowering plants draws moths, bees and butterflies to the same spot through the warmer months. In a car park outlook, even the comings and goings below become more interesting from a higher, padded perch that lets her look down at an angle rather than straight at a wall.
Build the indoor side of the lookout
Fit a wide, non-slip perch or a carpeted shelf level with the sill so she can stretch out instead of balancing on a narrow ledge. Place a scratching post directly beside it, because cats often scratch right after an exciting sighting to release the surge. Add a ground-level hunting corner nearby: a paper tunnel, an open cardboard box with two door holes, and a wand toy stored within reach. Rotating which toy lives in that corner every few days keeps the corner feeling new without buying anything extra.
Turn watching into doing, twice a day
Passive watching alone can frustrate a keen hunter, so pair the window with active play. Run a feather wand along the perch and down into the tunnel so the game starts where she already sits, letting her stalk, chase and catch in sequence. Two short sessions a day, one in the morning and one in the evening when cats are naturally most alert, suit a flat routine far better than one long weekend burst. End each session with a small meal or a puzzle feeder by the window so the hunt finishes with food, the way a real sequence would.
Signs the new setup is working, and when it is not enough
Within a couple of weeks you should see her choose the perch to rest rather than only to stare, with calmer evenings and less following you from room to room. If she still licks a bald patch, calls through the night or has gone off her food, boredom may not be the whole story and a vet check is the right next step, because skin, pain and thyroid problems can hide behind behaviour that looks like restlessness. Bring notes on when the calling and grooming happen, since timing helps the vet separate habit from discomfort.
Keeping the window routine alive on busy days
Window enrichment fails in most flats not because the idea is wrong but because the rotation and the play sessions quietly stop. KinsLe Care Teams helps here by letting you assign the morning and evening window play, plus the toy swap, to named people in the household, and each finished task is marked with a timestamp so everyone can see the lookout did not get forgotten today.