Certificate of identity issued from immigration Malaysia (for Malaysia permanent resident)

If my mother in law holding a certificate of identity issued from Malaysia, does she need visa to visit hong kong and Macau for three days only?
Can she apply the visa from hong kong embassy in Singapore ? If yes what is the documents she needed to bring along for application?
Can she apply through rush service application? If yes then does it mean she can be grant for min 3 weeks visa within two working days? Thanks.