I'm getting myself all confused over this issue.
The hours would be 8am to 6pm three days a week. The children attend nursery for 6 hrs on 2 of these days. I was thinking of charging maybe 1/3 or 1/4 of the hourly fee for the time they're at nursery. I would charge full fee if I had to look after them at any time during this period.
Here's where I'm stuck, and I need to clarify this before I mention it to the parents - what happens when the children aren't with me (eg on holiday during term time or sick days)? Would I charge for the 4 hours and the retainer fee, or the full 10 hours? I know the parents won't agree to this if it's the latter, and with the NCMA helpline closed until I speak with them I really need some help!