Why scent matters more than the item itself
A cat arriving at a cattery walks into a unit full of unfamiliar smells: cleaning products, other cats, new people. Against that, one blanket carrying the scent of home and of the cat herself is the fastest available signal that this space is hers. Cats rest their chin and cheeks on bedding, kneading and sleeping scent into it, and they actively seek that marked spot when unsettled. So the value of familiar bedding is not comfort in the soft-toy sense; it is information. Send the blanket she actually sleeps on, taken straight from her usual spot, and do not wash it first — washing removes exactly what you are sending it for.
What to send, and what to leave at home
Good candidates are a slept-on blanket or fleece, an item of your worn clothing if she likes sleeping on you, and one or two toys she genuinely plays with or rubs against. A hiding item is especially valuable for a nervous cat: a small box lining or a fabric hide she already uses gives her a scented retreat inside the unit. Leave at home anything irreplaceable, anything with sentimental value you could not forgive losing, and large collections of toys she ignores. Catteries launder bedding during longer stays and items occasionally go astray between units, so send things that matter to her, not things that matter to you.
Check the cattery's own rules first
Policies differ. Some catteries welcome personal bedding; others limit items for hygiene or provide their own bedding and prefer a single scented cloth. Ask when you book, and ask how they handle soiled bedding mid-stay, because a cat who will not settle without her blanket needs that plan agreed in advance. Label everything with her name, and make a simple list of what went in the bag. If the cattery runs webcams or photo updates, you will also enjoy spotting her actually using the bedding you sent, which confirms the choice was worth making.
Toys: familiarity beats novelty
A new toy bought for the trip carries no scent and no history, and many cats ignore new toys entirely when stressed. The scuffed mouse she bats around at home or the kicker she hugs and bunny-kicks is far more likely to be used, because the behaviour attached to it is a piece of her normal routine. Avoid anything with parts that could be chewed off and swallowed while she is unsupervised for stretches, and skip strongly scented novelty items, which add another strange smell to a unit you are trying to make smell like home.
The return journey for her things
Expect bedding to come home needing a wash, and wash it then rather than before — the scent has done its work by collection day. If an item mattered and it is missing, ask promptly, while the stay is recent enough for staff to trace it. Over several stays you will build a small, known cattery kit: the blanket, the hide, the two toys that work. Writing that kit down in her KinsLe Care Pass means whoever packs for her next stay sends the proven comforts, and cattery staff know which items belong in her unit from day one.