My eldest rescue cat - she's about 15 - has 'adopted' ds2 who is 7. She used to go to dh for cuddles, but gave that up when we got our second rescue cat. She now sleeps with ds2 and goes to him for a cuddle. She also follows him around and watches him.
When he was a newborn, she used to bring us live mice in the middle of the night - to presumably give to ds2 and also used to stay under his cot until he'd gone to sleep each evening.
ds2 is quite flattered, as she's usually vicious and evil.