For federal income tax purposes, you cannot deduct homeschooling or K-12 education expenses as an education deduction. The education credits are for higher education (college). 

Some states offer a credit for K-12 education expenses. Check with your states Department of Revenue to see if there are any tax breaks for homeschooling or private schools. However, these expenses may only be deductible if you claim the children as dependents.

@HelenC12   OP said My daughter paid me for homeschooling grandchildren,

Does that make her income self-employment, and the expenses are thus deducted as such?

You have a family interaction and nothing that needs to be reported on your income tax return.

As the other reply says no educational expenses are deductible, even if the kids were your dependents. 

However, if you daughter is claiming the dependent care deduction based on what she pays you, then you do need to report the income.  If you do the baby sitting/home schooling in your home, you report the income as self employment and deduct the expenses on Schedule C.  

In TurboTax (TT), enter at:
- Federal Taxes tab 

 - Wages & Income

Scroll down to:

- Business Items

   - Business Income & Expenses (Sch C)

The TurboTax interview will show you where to enter each type of  expense.

If you work in your daughter's home, you can still report it as self employment.  But you have the option of calling it household employee wages and avoid social security & medicare tax.  But, you  cannot deduct expenses, as an employee.