If my wife and I file separate this year can she claim the mortgage interest on the house and the child tax credit.

[DanielV01]

Yes, she can.  The caveat is that if she itemizes, you must also itemize, and this will lead to a larger (and perhaps much larger) tax due for you than if you were to file jointly.  However, this option is allowed.  (An additional caveat is if you are living in a community property state.  Then your situation is a bit more complicated).

If you have a prior tax debt that can be offset by the IRS, you can get the benefits of filing jointly (by having lower overall taxes), while at the same time receiving the portion of refund attributable to your spouse's income through filing an Injured Spouse form.  For additional information, please see this FAQ:  https://ttlc.intuit.com/replies/3326788