Agnes, sorry to hear about the loss of your mother. It’s sounds as though you have a similar relationship to me. I agree it is about quality of contact— although these days when I call it is because I know she is keeping older and so I should keep in touch.
I also think a little distance is healthy for families — you shouldn’t be living in each others pockets — this includes siblings as well as parents. And it does make for better relationships overall. For instance, I tend to make short visits home frequently rather than go for a extended stay once a year. Everyone can get along for a week or so I find :)
Thanks again for commenting!