I have edited my answer as follows:

Because the au pair is not subject to Social Security and Medicare taxes, you may be eligible to report the wages paid as the Child and Dependent Care Credit.  Here is a TurboTax FAQ with info about the Child and Dependent Care Credit:

https://ttlc.intuit.com/replies/3301418

Here is a TurboTax FAQ with the steps to enter the Child and Dependent Care Credit:

https://ttlc.intuit.com/replies/4395614

For more info from the IRS regarding au pairs, please click this link:  https://www.irs.gov/individuals/international-taxpayers/au-pairs

[Edited 04/03/2018 | 02:27 pm]

When I did this, TurboTax asked me for the amount subject to social security and medicare tax, and than the amount withheld. Because my au pair was a non resident alien, the wages I paid her were not subject to those taxes. When I entered $0, TurboTax told me I was wrong and would not let me proceed. So, how do I include the wages I paid for my tax return, but indicate that they are not subject to payroll taxes?

I have edited my answer above based on the additional information you have provided.  You will not need to do a Schedule H.  Instead, read my edited answer above for more info.