Im A Widow, exempt from taxes, but did with u all, what will i have to pay on $48.000 ?

Being a Widow does not exempt you from paying taxes on taxable income.

You can only be a Qualifying Widow for tax purposes for two years after the passing of your spouse and you have a qualifying child as a dependent on your tax return.  If you do not have a child as a dependent and you have not remarried then your filing status is Single.

Without knowing the type of income you are reporting, any deductions or credits for which you may be eligible, an answer to your question is not possible.

Complete your tax return and then you will know whether or not you will receive a tax refund or have taxes owed.