Before we adopted Mary two years ago from Rspca, we didn't know what to expect either as we had never had a rescue pet.
All they basically did was had a look around the garden, just checking that there wasn't any dangerous things left lying around, and made sure the garden was secure, also they suggested we get a cat flap and asked where Mary would sleep/eat etc, and asked a few questions about medical treatment/vet visits etc.

I hope your home visit goes well and you can take your girl home.

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Lynn, Mum to Buddy and Mary my two fur babies.