URGENT : HK VISA for Vietnamese

Hi,

My Sister-In-Law is a Vietnamese and currently holding on to a Work-Permit in Singapore. They are travelling to HK on the 8th November 2015. However, we just realised that for HK entry permit application, it will take about 10-15 days for full completion.

We already booked the air ticket and accommodation, possible to obtain an entry permit for her before the 8th Nov? My Brother is a Singaporean, we will be back to Singapore on the 12th November.

Kindly advice...
Appreciate your soonest reply.

Thanks,
Tricia