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

We have a son and daughter. Our son will need care on an as needed basis Mondays, Tuesdays, and Wednesdays. Our daughter will need care of Tuesdays only. Looking for someone for an as needed basis and possible sitter on a Friday ot Saturday night occasionally. We have help from my In-Laws, but they cannot help 100% of the time. We are will to guarantee time if needed. Schedule: Mondays- 7 a.m. - 4pm, Tuesdays 11 a.m. - 4pm, Wednesdays 11 a.m. - 4 p.m. $275 weekly when needed for the week. Pay varies depending on nightly sitting.