Mother cat is being mean to kittens

Our eldest cat, Jenny, had two litters of kittens this year. On litterwas born in the middle of March and the last litter was born at the end of June. We have one kitten left from each litter that we have kept. About two weeks ago, Jenny suddenly started being terribly mean to both of the other cats. She can be inside and they can be out on the patio and she will start growlin, hissing, and almost screaming at them. If they come near her she bites at them and slaps them and hisses and moans. We do not have any idea why she started this. At first, I thought it was because they were still trying to nurse, but that is not the case. If anyone has any suggestions, PLEASE let me know. She is a really sweet cat until she sees the other two kittens. Any suggestions will be greatly appreciated.

She is very tired of little ones at this point. Having litters that close together is very stressful and she is probably getting aggressive because of it. I would take her and get her spayed as soon as possible. It will bring down the hormone levels and she won't have to go through this again.

Sounds like Motherhood Burnout.
I agree with Sandie get her spayed, the poor little darling still feels responsible for them.

Tish

What I can't understand is why this cat hasn't been spayed before she had any litters, or at least after her first litter. Even breeding cats are only allowed one litter a year.
Please get her spayed ASAP, not only will she not be subjected to all this again, but you won't be contributing to the ever growing population of homeless cats.