How to charge for this??

[Adiamond]

Hi, I have just had an enquiry through a friend of a friend

This is what they want me to do---- Tuesday and Thursday 9am-1pm for 3 year old and then 9am-1pm mon-friday for the 3 year old and 6 year old sibling in school hols.

I don't know how to charge for this???
Can anyone please suggest how to do this? they are waiting for me to get back to them asap and I could really do with the work!!!

Thank you x x x

[blue bear]

I personally would want paying a retainer to hold the two extra days for 3 year old say 50% so would charge for 4 days in term time and 5 days in holiday and 5 days for older child but only in the holidays