I had a similar issue a while back. I ended up terminating them. I simply stated in my termination letter that I would be changing my hours and would not be able to accomodate them any further.

This is what I wrote:

Dear "daycare mom"

When I first started doing home daycare, it was with the stipulation that I would still be able to be there for my kids. We have been finding that my hours are starting to interfere with homework, dinner and general care of my own children. Therefore, I can no longer provide care past 5:30 to your family. Effective May 1st, my work hours will be 7 am to 5:30 pm.

Due to this, and financial reasons, I am unable to continue to care for "suzy".

She is a wonderful girl and I will miss having her around. I wish you all the best in finding a caregiver that meets all of your needs. Please feel free to give my name and phone number to another caregiver if they require a reference.

"Suzy's" last day of care will be January 30th. "

I hope this helps.

It's a really tough desicion to make.... You are putting your family first and that's a really important thing to do. I would start advertising to replace immediatly in case she bolts with no notice. I gave 30 days notice to this one and she stayed ( no choice, couldn't find another caregiver to do the hours)