you really don't have to have withholdings for federal taxes
With $32,000 of income less the standard deduction, the tax will be around $1325. That assumes you are filing Head of Household.
Then you will be eligble for the child tax credit which should be the same as the tax or $1325 (non-refundable credit) plus $600 for the refundable credit)
Then there is the EITC credit you will be eligible for which will be around $1600. (I assume you are under 65 years old)
Take all the numbers together and even if there is NO federal tax withheld, you'll still get a refund in the $2200 range comes next spring.
No need to have your employer withhold taxes, unless you want a larger refund next year.
