$5950.
Remember that her income is in the income bracket of $18,201 and $37,000, so she pays $0.19 per $1.
$1.19 = Taxable Income, which makes $1 after tax. To get $5000 after tax, the method is shown below.
$5000 * $1.19 = Taxable Income.
Therefore $5950 will be needed to earn $5000 after tax.