In the uk it is my belief that:
Childminders = are paid per hr per child in their own home. So £5 example above could be per child, and they have 3-4 children to look after from various families, maybe extra before or after school or in school holidays, which would be £15-20 per hour. Obviously, they have to pay for all bills related to childminding from that also so not rolling in it. They are self employed so decided their hours.
Nanny = work for one family, in family home. Paid per hr per family. So £15 per hour could be 1 or 5 children. They also help with day to day running of home related to child such as booking activities, organising events, buying new pants, sorting through outgrown clothes, cooking for child, homework etc. They are employed by family. They are generally more cost effective if you have more than one child, and provide an easier option as parents don't have to get child ready and take to and from childcare
Both of the above do not do general cleaning of the house. They clean up after mess has been made during the day by them and children ie from lunch, food prep and playing. If a child spills coco pops everywhere, then of course the hoover and dustpan comes out like a parent would. But they don't dust, mop, hoover, scrub bathrooms or similar.
A cleaner cleans everything. A housekeeper may clean, but also often does laundry, cooks, household errands, arranges plumber when problem etc.
Unfortunately, the Op here seems to be doing a full on cleaners job, with full housekeeping included, whilst also being a nanny to 3 children, but being paid the same as a childminder would for one child.