We have three rescue cats, all three of which we fostered, a 2 year old neutered male, a 1 year old fixed female, and a 6 month old neutered male. The problem is with the middle cat. She stays in my daughters' rooms much of the day, and will sleep on their beds. She's a bit stand-offish with my oldest, but allows my youngest to pick her up and carry her around regularly.
The problem is she doesn't like me (or my ex-wife) and will avoid me. If I approach slowly she will sniff my hand and occasionally tolerate me touching her chest, but usually skedaddles after the sniff. If I am able to hold her, if I pet her back her ears go back and she will fight and sometimes scratch in a panic or bite (sometimes hard but never breaking my skin). But occasionally I've been able to rub her belly and paradoxically she seems to calm down and tolerate it. She is like this with the kids, but to a lesser extent; clearly, she doesn't like being touched on the back, but I can think of no reason why as she's had no injuries or episodes that I'm aware of.
When she was a kitten she would sleep with me and the wife, and didn't seem to have any hangups about her back being stroked. One dynamic that has changed (other than age, and being fixed) is that the oldest cat (a 15-pound Maine Coon) occasionally chases and even bites her. The older cats both love the youngest cat, but seem to have a chilly relationship with each other. But still, I see her following the Maine Coon around sometimes after they fight, so I wonder if she's provoking it.
She's a beautiful cat (gray leopard-like colors) and I worry about her mental state and would like her to be more comfortable around all of us. I've tried giving her a variety of treats to find something to use to train her with, but she either doesn't like them or isn't willing to like them if they come from me.
Any ideas would be greatly appreciated.
2022 August Update: She's become more friendly in the last year. A couple of times a week she will come to me and sit on my lap and allow me to pet her, and sometimes lets me stroke her back. But eventually, she'll get agitated again and run off (and sometimes bite/scratch).