I switched my cat to an indoor cat in the 1990s when a diseased looking feral male cat showed up, and I didn’t want my cat getting sick.
I lived on a alley at the beach and built her a little bed and cage that stuck out into the alley about 5 feet off the ground, and with permanent access through the window, she had an opening that she could stick her head through to be petted and cooed at by passerbys.
The beach is heavy with cats and cat people, and she got tons of attention from all the people going back and forth to the beach and the pier.
I came to see that indoors was best, and probably won’t have an outdoor cat or dog again, that cat made it to 18 years with only one early vet visit for spaying and the initial shots, that really impressed on me the importance of keeping them indoors.
When everyone’s pets were outdoors in the distant past, pets didn’t seem to last long.
My cats live to be 18 on the average, but a lot of them make it to 20 and more-outdoor cats don’t have lives that long-even if they do have nine of them...
It sounds like your cat lived a dream life-her own penthouse and balcony overlooking the beach-every cat should be that lucky...