dont surrender at this stage and dont be afraid of going to the Labour Department because you have nothing to lose. The worst is to pay her wages for Feb, annual leave pay and air ticket only, so why not play the game with her?
According to the Employment Ordinance, you have to pay termination payment (including wages and annual leave pay) within 7 days from the last day of service, otherwise its prosecutable. So I advise you to file a counter claim with the Labour Department asap, and tell them that you are willing to pay her termination payment including wages, but unable to reach the maid and dont know how to calculate as she owes you one month wages in lieu of notice. Let the officer decides what you should do at the moment.