My Mum sounds very similar to your Gran, Donna. She had 4 children, always worked various jobs sometimes 2 or 3 cleaning jobs a day, my Dad worked away Monday to Friday as a long distance lorry driver back in the days of flatbed lorries he had to load himself, no motorways and not even a heater in his cab and so my Mum had to do everything at home herself.
If one of us fell ill it meant she either had to lose a day`s wages or send us to school come what may or IF she deemed us ill enough she`d farm us out to anyone who would have us for the day. We had quite a few nearby " Aunties" who were actually neighbours and so things such as measles, chicken pox and coughs and colds spread like wildfire where I lived. We all tended to go to the same Primary school and it was nothing unusual to have half the class missing especially during the cold months with chest infections, coughs and cold and the poor quality housing in our terraced streets with outside toilets, no bathrooms and no proper heating didn`t help.
I was in my last year at Primary School when I woke up feeling really nauseous, had a bad pain in my tummy and didn`t want to go to school. My Mum told me not to be so soft and sent me packing. Several hours later I was rushed off in an ambulance from school and by the time someone managed to track down my Mum at one of her cleaning jobs, I was already in theatre having my appendix removed. That was one of the very very few times in my life when I saw my Mum cry when she was sitting besides my hospital bed and stroking my hair.
Yes it might seem a hard way to parent, especially these days but she had such a hard life, worked her fingers to the bone, had no mod cons, no help and from her early 40`s had severe health issues herself which meant she passed away in her early 60`s. Plus it was the way 99% of us from the streets were brought up, it was a rough tough community simply fighting to make ends meet.