I'm making good progress with the black cat. Last night, the raccoons (I think) ate all of her food and carried away the bowl, so she was waiting this morning when I went to feed her. I meowed at her several times, and she answered each time. We also did the slow blink "I like you/I trust you" thing. Then, when I set out her food, she let me pet her! She held her tail in the air as well while I petted her, so I may be wrong about her having never had a home. At the very least, her mother had to have taught her that (it's a learned behaviour), so she's not entirely wild. Alexandra seemed interested and friendly. Black cat was a bit afraid of her (Alexandra is much larger), and gave a warning growl when she got too close, but didn't seem overtly hostile. Things seem to be going quite well.