is it wrong?

This shall sound probably horrible to the majority of folk that land up reading this blog, it wasn't going to be my first choice of a blog entry but its bugging me and I need to get it off my chest.
A colleague and friend ( one of the few I meet outwith work) her mother died on Saturday. She was very close to her and did a lot for her parents, the double whammy is, her dad is stage one dementia too.
Her mother went into hospital with an infection which then turned out to be cancer, which was too far progressed for them to do a thing, so for 3 weeks it was a case of waiting.
She passed in her sleep on Saturday morning.
She had all her marble till the last 3 days of her life.
Why is it wrong?
Well, I look at my mother, physically 100%, probably better than me.
She has no cognitive ability, she doesn't want to live in the house we have been in since 1962.
She doesn't know anyone, and she now wears nappies.
He quality of life must be awful for someone that until her late 80s worked 12 hour days.
And yet, she is 100% fighting fit ( and that word fighting sums her up) and seems to be going on and on.
It just doesn't seem right that someone in their 70s with all the faculties who is looking after a beloved husband and living an independent life has her life cut short, while mine keeps going oblivious to the world around her.
Sounds awful, while my colleague is devastated her mother has passed over, it made me think, will I be when mine goes?
Doubt it, I think I've done my mourning now, which sounds harsh but the person inhabiting her body isn't my mother.
Sounds harsh and yes I will miss her, but probably not in the way my colleague is missing hers this morning.