Tiny the Aggressor

[Cathyday007]

Almost 3 months ago I brought home a cat that had been living outside for about 10 years at a local golf club. She'd always fended for herself but during the first lockdown last year she almost starved to death. Thus I and a few of the other members started feeding her. When it looked like we were going into another lockdown in November I decided to bring her home with me.
She spent the first couple of weeks in a dog crate in our shed until the weather turned cold when I brought her into our spare bedroom. She's settled really well into indoor life and is becoming very affectionate.
Trouble is, having gone through slowly introducing her to my 2 existing cats, she keeps attacking them. By day my 2 existing boys are generally outside whilst Tiny spends her day upstairs in her bed in our bedroom. She comes down for tea and then stays to watch TV on my lap for the evening. However, if either of my other cats appears she just goes for them, hence we're living on our nerves at the mo waiting for her to attack. Strange thing is I can feed them all together and they rub noses whilst waiting for me to put their food down.
I keep them all separate where possible to keep the attacks to a minimum but I feel that's not getting them to know each other better. I've tried playing with Tiny to reduce her aggression but she's not interested in the slightest. She does chase a laser pen but gives up after less than a minute.
I really want to keep all 3 cats but we need to lessen our stress levels and get them all in the same room without her going on the attack.
I should add I've already got Feliway Optimum on the go all over the house.
Does anyone have any suggestions as to what we can try?

[Mollycat]

Sounds to me like you need to go back a few steps to where she was comfortable and build back up even more slowly. Trouble is once they have had the opportunity to create a negative experience it's hard to undo, it's a setback but you can do it. At each small step of introductions they all need to be comfortable and keep things at that level for at least a week. Otherwise if you try to take the next step too quickly when they are only just ok with the last step, you keep them in a constant state of tension and fear. They all need to be comfortable enough to relax together without the opportunity to attack or chase. It will take more months.

[Cathyday007]

Thank you. I'll continue to keep them all separate for the time being then except maybe at meal times when they seem to get on.