Heather - you have to be proactive on those kind of sites too. Don't just make a profile and wait for people to contact you. Do a search of opportunities to see who is looking for a nanny/babysitter and what their exact needs are. Then you can apply to them and let them know you're interested.

Hi Heather: Thanks for posting to Jobcase! If you're looking for babysitter jobs, I recommend joining a site like Care.com, where you can find clients who are looking for babysitters and nannies. Hope this advice helps!