On your mother's tax return, the instructions that DaveF1006 gave you will take her to a screen that asks "Did you receive any other wages?" When she selects Yes, the next screen is specifically for entering household employee wages. Ignore the note on that screen that says to only report income less than $2,700. It does not apply to your mother's situation. Enter the full amount that you paid her, even if it's more than $2,700. The income will be reported on Form 1040 line 1b, which is where it belongs.
