Yes! You set the rate you want to charge, and changing this rate is simple!
Click the "My Account" tab in the bottom right of the app. From there, look for the "My Hourly Rate" tab and click that. This screen will let you change your hourly rate and provide you with helpful information about the rate you are charging.
Please also note that your rate will not change for previously booked sits. When a parent creates a request, your rate at the time of the request is locked in for that sit request.