"Help us call RSPCA ... or cat's protection they won't help me," the note said. Shocked, Sheridan took the kittens to her mother, Sue, who has lots of experience caring for cats.
"It wasn't very nice inside the case, and there was a cloth with blood on it, which we think the mother had probably given birth on," Sue Sheridan told the Warrington Guardian.
After a checkup with a veterinarian and plenty of care, the kittens are doing much better - and the family plans to keep three out of the litter.
"3 of them will be staying within family. myself my mum and my nana all will be having one," Kaysie Sheridan wrote on her Facebook page. "Though we do not want to promise homes to anyone at the moment as they're still very young."