Young french-portuguese family looking for an au pair

We are a young family looking for an au pair to take care of our two girls. Clara is 7 years old and needs to be taken to school at 8.30 and collected at 3pm, Claudia will be 27 months and will need looking after the whole day while we are both at work.
We would like someone to be able to speak French with the children.
We speak mostly English at home,but we also speak French and Portuguese.
I am Portuguese and I have been living in the UK for 20 years,my husband is French from Toulouse.
We are looking for a responsible and friendly au pair. The au pair will not need to cook, just do some cleaning.
We would like someone to stay with us for a minimum of 12 months. It's necessary that the au pair can drive because the Clara's school is 5 minutes away by car. My husband will give the au pair as many lessons as necessary for the au pair to feel confortable driving,but where we live it's very easy to drive around!
The au pair will be free from 5pm and also Saturday and Sunday. We don't require any babysitting in the evenings.
Starting date 28/08/2012

We live in the beautiful borough of Bromley which is 15 from Central London by train. We have a semi-detached house with 3 bedrooms, there is plenty of living space, a garden at the front and at the back of the house, 2 bathrooms, 1 conservatory.
It's located in a cul-de-sac and it's very residential.
Bromley centre which has plenty of shops is 5 minutes drive from the house.