I know exactly what you mean. I have four cats that live in my house and I have one feral girl, my Arwen, who lives outside. But I feed her regularly and she even started sleeping in my garage at night during the very cold winter months. But I don't say I have five cats. I feel guilty about it sometimes. She is a TNR, she has lived in my neighborhood for possibly 8 years or longer, but I have fed her for a little over three years now. My street is very quiet, and everyone knows who she is. I don't really consider her mine because she loves my neighbor and her dog as much as me. She waits for them every night when they get home from work and they walk their lab, and she waits for them, and they pet her and love on her, and she LOVES their dog. She rubs against the dog and throws herself in front of the dogs path as they are walking, it is hilarious. There is no other dog on our street that she acts like this towards. She spends almost as much time in their yard as she does mine, so I don't really consider her mine, but I adore her as if she were mine. I am the one who tamed her. For a few years before I managed to get her to take food from me, I tried and tried, but she would run. We would only see her at night on trash days, when you put the trash out, she'd be there. But you could leave cat food next to the trash, and she wouldn't touch it. When she finally did start taking food from me, she would belly crawl up to the food, hiss at me, inhale the food in 4 bites, and run away. We have come a long, LONG way since then. But she still has no desire to be inside, she continues to live in the 3-4 yards on my street and everyone knows her.
That is so sweet that you and your friend care for these ferals. I'm sure many of them would not be around any longer if it were not for you. This is a wonderful thing you all are doing for these cats.