Babysitter Needed for my Children - Full-time / Part-time

We are looking for a great babysitter for 2 children in New York. We would prefer a babysitter who does not smoke and who has college degree. We need help with after school pick ups on Monday to Tuesday plus Friday starting at 5 p.m. to 6 p.m. (pick up from afterschool and dropped home). Wednesday to Thursday from 2:30 p.m. to 4:30 p.m. (pick up from school and brought to soccer). Everything local to the UWS. Any combination of these would also be OK. Wednesday and Thursdays are the biggest concern!