A photo of Twinkle's shaved tummy, after her operation. The vet did a fantastic job with the incision - it looks like a small belly button, and was a very neat stitch. She's healing just fine, and is acting pretty normal now ... except for the sleeping on the laundry bit. Which, as I gather, is actually pretty normal for cats anyway.
PS: K has just reminded me that Twinkle was sleeping on the laundry long before the operation, so I guess she's just being normal for a cat.