First time nanny- Am I being treated fairly or taken advantage of??

So this is my first nannying gig. I’ve been on for almost a year. After meeting and talking to other nannies in the community I’m starting to think maybe I’m getting screwed. Not only do they all get paid more, reimbursed for mileage, etc. they also all get paid hourly and never have to “make up hours” (ex: the kids were with their dad one Friday so I didn't work, therefore I worked on Saturday for free to make up "for my day off".)

I get paid $750 a week (take home like $640) regardless of how much or how little I work. I typically work 53-60 hours minus any time they are with their dad (but then I make up that time in the evenings or weekends)

When I go on trips with them I do not get paid extra either (all though she does cover all my trip expenses), even though I don’t have anytime by myself. This past trip I had to share a room with the children so I was responsible for them literally 24/7

Also my job responsibilities include making dinner and doing laundry for the mom. Grocery shopping, running to the liquor store for her, picking up her dry cleaning, paying her bills (with her credit card), calling her doctor to get her rx refills (i.e stuff that has nothing to do with the kids)

Also want to add I’m located in NC