An old cat

I have an old cat sitting next to me my Girlie-Girl. I don’t know when she got old; I’m not even sure of her age. She could be anywhere from 9 to 13 years old, which I think is young for a cat getting old.
She feels lighter than she did when younger, as though her form has been filled with air. She’s not skinny; she’s not even smaller than she’s ever been. She just feels less substantial than she had. She’s in fine health despite it, and other than a touch of arthritis she has no health complaints.
She yowls in a cranky way when she’s not in the room with us. If we call out for her the yowling settles into a calmer meow, almost like she has found her way again. I wonder about dementia; as there’s nothing to be done about that, we just live with her peculiarities.
Cats’ lives
Cats live for a shorter lifespan than we do; it’s just reality. The average indoor cat lives on average 13 years of age, but keep in mind that some cats die younger and some much, much older. I’ve had cats live to 19 and 20 years of age. To be a cat owner is to watch your beloved cats die before you. (I have seen seven of my cats die in my 57 years of existence, including a newborn foster cat. Which averages out to 13.)
So Girlie won’t live forever; at this point it’s hard to say when she’ll die. If she’s like most tortoiseshell/calicos I have known, she’ll live to 19 or 20. But it’s hard to tell. For now I’m going to have to enjoy her and keep an eye on her.