Over bred?

[NCCAT]

Someone I know ,has had 4/5 litters from her cat in 2yrs.
It's a pedigree breed & the breeder is registered.
The cats are , from what I know , well cared for But imo, Has been bred from too much.
What would you consider over breeding from a cat?
Would you report it & if so, where?
Thanks

My cats were rescued from a kitten farm. They were five when I got them. I dread to think how many litters they'd had. It took them along time to recover and one died aged only eight. Her kittens will almost certainly have inherited her heart condition.