One room is a kindness, not a restriction
A whole house is an overwhelming amount of new information for a kitten who has just left her litter, and kittens cope with change by mastering a small territory first. One room gives her a complete world she can learn in a day: where the tray is, where food appears, where she can hide, and where she can sleep undisturbed. From that base she will ask for more territory herself, scratching at the door and watching it with interest, which is the signal to expand gradually, room by room, rather than relocating the tray and bed into new spaces all at once and resetting her confidence each time.
Lay the room out in zones
Arrange the room so its functions do not collide. The litter tray belongs in a quiet corner as far from food and water as the room allows, because cats keep toilet and dining separate by instinct and a kitten forced to eat beside her tray may avoid one or the other. Her bed and hiding box go in the calmest corner, ideally with a view of the door so she is never surprised by arrivals. Food and water sit somewhere she passes often, and the scratching post goes near the bed, since kittens scratch on waking. Keep the layout fixed for the first days, because she is building a scent and memory map, and every moved item is a small piece of relearning.
Kitten-proof at floor level before she arrives
Get down on the floor and look at the room as she will meet it. Block gaps behind wardrobes, washing machines and heavy furniture that she could squeeze into and not reverse out of, and check under reclining chairs and sofa beds, which are dangerous traps for small kittens. Lift or cover cables, secure blind cords well out of reach, and remove small objects, hair ties, string and anything else she could swallow. Move medicines and cleaning items into closed storage, check houseplants in the room against advice on plants unsafe for cats, and remove anything heavy from low shelves her first climbs could bring down on her.
Your behaviour in the room matters as much as its furniture
Visit often, but let the room stay calm. Sit on the floor and read, let her investigate you at her pace, feed meals in the room at predictable times, and play gently with a wand toy so the room fills with good associations. Keep household noise and visitors out for the first stretch, introducing both gradually once she eats, plays and uses the tray confidently in front of you. Watch for the basics that say she is settling: eating within the first day, using the tray, and choosing to sleep in the open rather than only in hiding. A kitten who has not eaten, hides continuously and startles at everything after the first couple of days deserves a call to a veterinarian rather than more waiting.
Share the room's rules with everyone
The safe room fails when a well-meaning person carries the kitten around the house for a tour, moves the tray while cleaning, or lets the dog in to say hello. Write down the room's layout, the visiting rules and the expansion plan where the household can see them, and brief children on floor-level behaviour before their first visit. KinsLe Family Sharing keeps those first-days notes with your kitten's profile and care details, so every family member who helps maintains the room the same way and she learns one consistent map.