My cat is a horrible bully

[Horriblewoman]

How can I stop her being awful?!

We have sisters who are now 5 and over the past year ‘my’ cat constantly attacks her sister who is more bonded to my husband. Jumping on her when she’s sleeping, stalking her around the house, pinning her to the ground, biting her. It’s way beyond playing and feels really nasty with lots of growling and hissing involved. They are both incredibly affectionate with us.

Any tips for making them best friends again? They used to get on so well!

No advice really. We had a similar situation with our litter mate sisters. They were so close as kittens, did everything together, then gradually became more distant.
By the time they were 5 or so they would become irritable and duff each other up occasionally, but it was never that bad.
They just found other places to sleep and play etc..
When one died at 19 years old, the other one flourished, and was much happier. Cats are funny little creatures.
Hope you can sort it out.

A Feliway friends diffuser might help.

Having separate eating, sleeping, toileting areas if at all possible

Having said that, my two litter mates are over 17 and have never been friends!

We set up two litter trays and they still insist on using the same one 😁 literally untouched for months.

And multiple sleeping areas around the house but always hang out together, it’s like they’re actual human siblings winding each other the whole time and not realising the solution is to go to their own rooms!

Probably just jealousy. One of ours only wants to sit on a lap (not normally a lap cat) if the other is already there, despite there being another lap, acres of comfy sofa, various cat beds etc to choose from. Illogical little things aren't they

Definitely get the felloway friends diffusers. We have a few dotted round and you can tell if we haven’t spotted they’ve run out! They go from all sleeping on our bed to grumping with each other. Might also be worth getting checked out with a vet if this is unusual as pain can cause these types of changes without any sign of pain showing as cats mask it. Never tell off the aggressor as usually that only perpetuates the issue.

Is it true aggression or is it pent up energy and the other cat just doesn't like it?

Do they go outside? If not, do you play with them a lot?

You can also get a spot on felineaway which I used when introducing new kitten