If you gave her the correct information about where to send the check, then you are not at fault in causing this and should not be liable for the stop payment fee. Rather, she should have to absorb the fee as part of her obligation to pay you your wages--to make sure the money gets to you. Only if you caused the delivery problem (e.g. provided the wrong address) should you be liable for the cost.That said, if she refuses to acknowledge that she should pay, you would have to sue her to get your money. You will get your check much faster and with less effort if you pay the cost for her.