All income tax refunds can be taken to pay back child support ... always and forever. If your stimulus money was on the return as a credit on line 30 then it too can be taken.
On the return child support is not a deduction and if you are an employee getting a W-2 paycheck then the employee business expenses are also not a deduction on the income tax return.
Child support is never tax-deductible. Even though the money is garnished from your wages, it still counts as money paid to you, as if you had received the money and then written a check for the support out of pocket. It’s still taxable wages to you even though it was paid to someone else.
Work-related expenses used to be deductible subject to the 2% rule, but that deduction was eliminated for 2018 through 2025 by the tax reform law, which also doubled the standard deduction. Your employer can reimburse you for legitimate expenses tax free if you provide receipts. You may want to discuss the reimbursement situation with your employer, if you have been paying substantial amounts of money for work related supplies. Depending on your state law, your employer may be required to provide you with or reimburse you for protective gear needed for your job.
Tax refunds can be held by the government to collect certain debts, including back child support. Only the $600 round 2 stimulus payment was specifically exempted from collection efforts, but if you did not receive the stimulus payment and claimed the rebate on your tax return instead, that would be subject to collections.