Well, last night Lucy curled up inside the treehouse and as far as I can tell, stayed there all night. She went back in this morning after breakfast. So a success! Ed very happy, all his work and she likes it, not a given as every cat owner knows cats are so finickity.
Got up after a rotten nights sleep to find both knees are painful, can barely walk. I guess the old bones are wearing out :-( Old age sucks. My b'day was on Sunday and the aches started on that day, lol, like an unwanted present.