Last year, before she went home, I paid her salary in advance and then we experienced one long long evening waiting for her when she didn't come back on time (luckily, it's only half day delay but she came back after 12am without a call!)
This year, given her normal pay date is month end, I plan to let her go home in the middle of the month and pay her salary only when she comes back (i.e. normal pay date). I think one month salary is one more reason she needs to consider when she plans not to come back! Hope it works!