Your hotel sets guidelines for the sitters to follow, to protect their guests and sitters. These vary from hotel to hotel but are similar, so check with your hotel's concierge  what the current rate is what your sitter should charge you. Report a sitter at the concierge if she is overcharging you!

Here are some of the general guidelines:

The charge per hour varies between US $10 - $12 per hour for one child;

$1 will be added per extra child.

Usually it is $10 at the Low-rise hotels and smaller resorts,

$12 at the High Rise hotels like Hyatt and Marriott.

Radisson is up at $15 an hour ($2.50 per extra child)!

There is a  charge per hour;  daily-rates or weekly-rates are not applicable.