The first meeting should be short, ordinary, and entirely on her terms
A cat learns who is safe by watching them behave predictably in her territory, so the first sitter visit should look like almost nothing: the sitter comes in, sits down, talks to you, and lets the cat decide whether this new person merits investigation. If she approaches, the sitter can offer the back of a hand to sniff and a treat placed nearby rather than thrust toward her. If she watches from the doorway or stays under the bed, that is also a successful first meeting, because she has logged the sitter's voice and smell without anything alarming attached to them. What must not happen is retrieval: carrying a cat to a stranger for inspection teaches her that this person predicts being cornered.
Let the sitter become the source of something good
On the first or second visit, hand the best jobs to the sitter. Let them put down her favourite meal, trail her beloved wand toy, or offer the treat she only gets on special occasions, while you stay present but uninteresting in the background. A shy cat may eat the food only after the sitter leaves, which still counts: the association between this person's visit and good things arriving is forming either way. Keep visits brief enough to end before she tires of the company, and spread two or three across the days before a long trip rather than staging one long audition the night before you fly.
Walk the routine together with the cat watching
Once the sitter is a familiar face, do a full rehearsal visit: they prepare her food where it is kept, in the amounts you use, clean the litter tray, and find the carrier, while you correct the small things that written notes never quite capture, like the scoop that lives behind the bag or the door that needs a hip against it. Your cat watching her routine performed by the new person, in the right order and places, learns that the pattern of her day survives your absence. This is also your chance to judge the sitter properly: how they move around a cat, whether they ask questions, and whether they write things down.
Show the sitter the cat only you know
Use the visits to pass on the knowledge that separates adequate care from good care for this particular cat: where she hides when the doorbell rings, the windowsill she must not be shut away from, how she asks for food, the difference between her relaxed sleeping spots and her unwell hiding spots, and what she does when she wants company versus solitude. Demonstrate how she likes to be handled, if she likes it at all, and be explicit about anything forbidden, from open windows to particular rooms. Encourage the sitter to take their own notes and photos of setups, because a photo of the feeding station beats a paragraph describing it.
Agree the travel-day pattern before you need it
Finish the introductions by settling logistics while everyone is calm: how keys change hands, when the first visit happens relative to your departure, how often updates come and in what form, and what the sitter should do and who they should call if she hides, refuses food, or seems unwell. Leave your vet's details and your emergency arrangement confirmed, not assumed. A cat who has met her sitter twice, watched them run her routine, and eaten well in their presence is starting your holiday from familiarity, and that is the whole point of introducing them properly.
Pairing those visits with a KinsLe Care Pass for the sitter means the routine, hiding places, and vet information they saw in person are also written down for them, so nothing depends on remembering a single tour of your home.