4 day a week nanny

We are looking for a caring, fun, engaging person to look after our 2 year old daughter and 9 month son (will then be almost a year)for 4 days a week, from about 8.00am until 6-6.30pm. Duties will include meal times, washing childrens clothes, play activities, trips out and the odd bathtime.
Start time will be at the end of April and live in status could be possible. Applicant must be non-smoking, but doesn't need to drive. Previous nanny experience and references will be expected.
We are two professional , laid back people, who would like our kids to remember their childhood as a fun time.
Salary to be negotiated at interview.