How much would you pay your babysitter to babysit?

I have a serious question and it's just out of curiosity (well kinda). So if you had three children and you were working ridiculous hours how much would you pay the babysitter? Would you pay them hourly? So I am babysitting three children ages 9, 12, and 13. I am babysitting them for 15-16 hours each day for 6 days. The mother of the children said she wants her house clean every day so I basically scrub it everyday and the kids maybe pick up a few things but do whatever they want really (mind you I'm 28 weeks pregnant and I get tired very fast and get very bad Braxton hicks contractions from bending over so much and moving or at least that's what I think they are). She also expects me to drive them around everywhere but doesn't give me gas money and I don't have the gas for that so now her kids are angry at me for not driving them where they want to go (also her kids don't listen what so ever and are constantly doing things they shouldn't 🙄). I do not have a job as I am in between them and am doing this so I can pay my car payment. At the end she said she'd pay me 200 dollars. Am I being a little petty about how much she is paying? I just feel like 200 isn't enough for 15-16 hours for 6 days and having to drive her kids around with my own gas money.

Please I don't want any comments saying something like "if you're pregnant you should have a steady job" or "why are you pregnant if you are in between jobs". Please no judgmental comments I just wanna know if I'm being much. Thank you

Also I'm not sure where to post this so if you know where I should please recommend