A big gathering changes a house in ways a cat notices first: doors opening, voices overlapping, cooking smells, furniture moved and strangers crossing the hall. Her protection is not training her to enjoy it. It is giving her a finished refuge and a day that stays predictable behind its door.
Set Up the Escape Room Days Ahead
Choose a room far from the main gathering space, music and the front door, and build it before guests arrive, not on the morning. Put her litter tray in one corner, water well away from the tray, bedding in a sheltered spot and a scratching post where she can use it, and add a hiding place such as a box or covered bed so she can choose invisibility as well as rest. Check windows are shut or securely latched and remove anything breakable, chewable or scented that a stressed cat could knock over or investigate.
Then let her live in that setup for a few days beforehand. Feed some meals there, play with her there in the evening and leave a worn item of clothing near her bedding, so by the gathering day the room already smells of her and of ordinary life.
Move Her In and Brief Every Guest
On the day, move her into the room before the first guest arrives, while the house is still calm and you can do it without carrying her past bags, coats and open doors. Go in with her, settle her food and water, give her a few quiet minutes and leave her with the door shut. From that moment the shut-door rule belongs to everyone: the door stays shut, it is never propped open for air or conversation, and anyone who must enter knocks, opens it narrowly and closes it straight behind them.
Brief guests as they arrive, briefly and warmly, before someone goes looking for the cat. Say where she is, that the door stays shut, that nobody pops in to visit her, and that children may see her only with an adult present and only if she approaches them; there is no lifting her out for introductions and no passing her around. Put coats and bags where guests will not need to keep opening her door, and agree who checks the hall and front door during arrivals, because a cat who slips out of her room still needs the outer doors closed against a bolt.
If a guest is staying overnight, repeat the rule for the night hours, when a half-asleep visitor may be the one to leave her door ajar.
Keep Her Day Normal Behind the Door
Keep her feeding and play times at their normal hours throughout the gathering. One familiar person should slip in quietly for those jobs, topping up water, checking the litter tray and offering a short play session or calm company if she wants it, then leaving her in peace again. A rotation of different relatives checking on her turns care into a visiting schedule; one known face keeps it routine.
Watch the evidence that she is coping: food eaten, tray used, some rest or play during checks. A cat who has eaten nothing and stayed wedged in hiding all day needs the noise reduced, the checks kept to essentials and, if that picture continues after the gathering, a word with a vet. During evening noise, fireworks or party music, keep her windows and the house doors closed, stay unhurried around her room and leave her to choose the hiding spot she trusts.
When guests leave, do not reopen the whole house to her at once in a burst of tidying and door-slamming. Let the house go quiet first, open her door, and let her re-enter each room at her own pace, with meals and play kept at their usual hours that evening too. Her profile can be opened by family members you pick under KinsLe Family Sharing.