My maid worked in Taiwan for 2 yrs and in Saudi Arabia for some years. So her mandarin is good. It is easy for my parents & kids to communicate with her. At least my daughter now in P.3, she knows some Mandarin. After working here for 1.5 yrs, her Cantonese is O.K.
My yan yan worked in singapore 2 years. She come to my family 1month, so far so good. It is better than no experience bun bun, I employed 2 bun bun before, I need to expend 2 months to train them. It suffer experence.