You just need to provide a one-way ticket back to her home. The date of the ticket has to be able to amend. The date of the ticket can be the same date of leaving your home.
My agent said that as it's close to Chinese new year, it's difficult to get air ticket, and the price is much higher. And the air ticket better to be open, at the last day of the 14days grace period. But you know, agents are rarely honest