Employers are required to add "expense allowances" to your W-2. They are not required to add actual expenses reimbursement.
If her employer has her submit a detailed expenses claim form, for reimbursement, as opposed to giving her a fixed amount for expenses, it should not be added to her W-2. They are doing her a disservice by doing that way, as the schedule A and 2% rules prevent her from deducting all her expenses.
See https://www.lburdickassociates.com/employee-reimbursements-under-accountable-and-nonaccountable-plan...
