I've heard of some females going into heat a young as 4 months old so this is why I wanted to have my Ziggy spayed before she was even this old. A lot of vets won't spay them until they're at least 6 months old but by then some of them have already gone into heat. As long as your kitten is healthy and has had her shots and weighs enough, she should be okay to be spayed.

How old is your kitten?