How much would you pay a college student as a summer nanny?

Does it depend on how many kids you have? Do you pay by the hour, or day as a whole?

Here’s my specific scenario:

I work Mon-Thurs 8 AM to 5:30 PM (almost 10 hours/day, 36+ hours/week)

2 kids, ages 10 and 12

I get paid by the day, not the hours

I get $50/day, $200/week

**And this is not the first summer I’ve nannied for them

My friends think I get grossly underpaid, but as they’re my friends, that means they’re all my age. I wanted some adult/possibly parent perspectives on my situation.

How would you pay a nanny? Am I getting paid a fair amount?