It sounds like your female cat reacted to the returning male as if he was a strange cat. So she has become aggressive, and is blasting out at any other cat around, which unhappily is the kitten. I had a friend with two cats, each of whom became aggressive if her friend returned from a solo vet trip. He concluded that the cat who'd been to the vet must come home smelling strange. Your male would certainly have been in contact with antiseptics etc. I have also seen in my own cats that on the odd occasions when one has spotted a strange cat through the fence, and gone into territorial protecting mode, growling with tail up, then this aggression has transferred to sudden attacks on my other two cats. This leads to confusion and hurt feelings.

So to me the behaviour you are seeing is not usual, but not that uncommon. I think you are doing the right thing keeping the female separate for now. My experience is that things usually settle down in 24-36 hours, but you need to protect the kitten. It must be horrid to be attacked by one's mother, but the male cat should be a comfort. Give it the rest of today to settle down, feed them in their separate rooms, then maybe see what things are like this evening.

 

I agree with @blackislegirl about why she's suddenly attacking the male & the kitten. Hopefully she will calm down in a day or two, and at 8 weeks the kitten isn't totally dependent on her for food. However keep a good eye on it's eating - it's highly unlikely to be fully weaned.

Your male will still be fertile, for up to 10 weeks or thereabout. Same is true of men who get a vasectomy - they have to continue to take precautions until two satisfactory sperm tests. So you need to keep him apart from the female anyway - she is very likely to come into call again with an 8-week old kitten, if she's not already done so. Cross fingers you don't have a surprise litter on the way. Hope she is getting spayed soon.

 

If the kitten as mentioned in the double thread of the same post is still being rejected by the mother, then it may now be best for it's own safety to leave it with the dad and hand feed the little one. If it is about 8 weeks old then the kitty will be able to be fed safely by hand or use a larger volume syringe and use a pate style food that can be mashed and a little water added to make it easier to feed.

The kitten has her dad aroma so this is being detected by mum and so she rejects her by force and displaying aggression.

 

If the kitten as mentioned in the double thread of the same post is still being rejected by the mother, then it may now be best for it's own safety to leave it with the dad and hand feed the little one. If it is about 8 weeks old then the kitty will be able to be fed safely by hand or use a larger volume syringe and use a pate style food that can be mashed and a little water added to make it easier to feed.

The kitten has her dad aroma so this is being detected by mum and so she rejects her by force and displaying aggression.

Will she never accept the male cat and kitten again?

 

The male has only been neutered for less then a week so he needs time for his body to adjust and the toteseterone levels to drop, the fact tht kitty is ok with him does allow her some comfort and feline company at such a young age when he/she looks to being rejected.
The mother is in an up/down spiral all the time she remains fertile, one will need to get her spayed and then reintroduce both in the hope that eventually they all get on. The kitty at 4 months or so will need neutering as well.
Some felines react to being away and vet or other animal aroma's they return with.

Mr Tom once reacted for 24hrs to his late hosuemate Button when he came bck from the vet following a claw intrusion in to a pad, when Tigger was spayed back in April last year their was no such issue.

 

Until both the adults are neutered and their bodies have calmed down, then one may not see harmony.

 

Her being in call might not be helping matters.
As he's still fertile for several weeks after neutering its best to keep them fully separated for now anyway.

I do know of case where several months down the line the cats didn't get on after one had been to the vet.
They got a behaviourist in and things did improve to the point they can tolerate being near each other.
They had been close, sleeping next to each other etc beforehand.

 

I am sorry to read that the issue continues. I have no experience of breeding but am not surprised by the opinions above that hormones will be involved. As to the kitten, I think he/she will be ok with the dad. Male cats can have some innate parenting skills - 18 months ago my own dear Rufus took good care of two new kittens, showing them the ropes as it were.

Is the original poster in India as their flag suggests? Perhaps that makes a difference; there might be other things going on that we don't see in the UK.