Babysitter - Full-time / Part-time

We need a sitter for our 3 daughters in Mansfield. We're looking now to begin the week of August 31. We need help with overseeing that they stay focused on homework, after school responsibilities and with transportation to/from their activities. Ideally someone experienced with older kids - perhaps some teaching experience. For reference, our girls are entering 10th, 8th and 5th grade. Please be comfortable with pets - we have a lab.