I spent some time in "Lucy's" room last night. Ringo badly wanted to meet her, so I let him in. He must be the model cat for introducing himself. He walked around the room quietly, smelling and looking at everything. He slowly approached Lucy. There were a few quick hisses, but mostly contemplation of each other.
Ringo was in the room, hanging out, for at least a half hour. It went very well!
This morning, Benny peeked into the room. He just watched her (from a distance) while she ate.
It's amazing what a few days can do. She is looking much healthier already.