Jean,
Thank you for saving two kitties lives. They will warm up to you in their own time - especially when they realize the can opener requires your help to feed them.
I haven't had a cat in many years, but, I can tell you it can take two weeks or two months for them to feel at home. Even dogs have their own timetable. When we rescued our dog, Gizmo, we thought he would never bark or speak. One day, after having him three months, somebody walked on our front lawn and he barked the deepest baritone bark we'd ever heard. He's a Lhasa Apso and you'd have thought we had a German Shepherd from the sound of his barks.
Enjoy your new babies. Love to see photos!