Sounds like the OP's assistant along with her hubby will be very comfortable in one of Melb/Syd's leafy inner city suburbs, and likely will be employed by a professional firm that would adhere to state governments workplace anti discrimination/harassment laws which tend to have extremely sharp teeth if you get caught up in a complaint. People have been sacked for as something as simple as an inappropriate email....
Interesting to note that the Chinese have existed in Australia since the first fleet, via the spice/tea trade to Botany Bay when the colony was first set up. Melbourne has had two Chinese Mayors, one that was sworn in and did a great Job, my mate John So, and a very old family friends father, who unfortunately died before he was officially sworn in as what would have been Melbourne's first Chinese Mayor in the late 70's.
The Chinese community have done very well in Melbourne/Bendigo/Ballarat and they have integrated very well thanks to some of its better known members via the Australian Chinese Chamber of Commerce, and a few that make appearances on Morning Television cooking shows etc etc and have done for many years. Anybody who says that Chinese get a tough time in Melbourne is full of shit in my experienced opinion.
Majority of my AUSborn and Hongkie Chinese friends who work in Melbourne, work for very large corps like IBM, PWC, Toyota etc etc etc, a couple of them own very well known Chinese restaurants, one owns a Chinese medical clinic that specialises in acupressure / acupuncture and a couple of pharmacists.
They'll be fine once they figure out where best to live in relationship to where they'll be working and proximity to schools etc if they have children. Cost of living might be a bit of a shocker at first, but once they get over that, things should be all good.
If they are considering Melbourne, areas I would highly recommend to them that will be comfy / nice upper middle to upper class suburbs that are easy to access the CBD by car/train/tram would be as follows. In order of more expensive very established inner city areas to 'outer' eastern suburbs...
Williamstown
St Kilda
South Melbourne
Port Melbourne
Albert Park
Middle Park
Parkville
Carlton
Richmond
Toorak
South Yarra
Armadale
Prahran
Malvern
Kew junction
Studley Park
Balwyn
Canterbury
Surrey Hills
Boxhill
Forest Hill/Blackburn
Glen Waverley
Mount Waverley
Titus, your friends will figure it out, the HK birdcage isn't going to be everybody's cup of tea, even amongst members of the Chinese community who have a more open/adaptive/enthusiastic view of the world. Quite fortunate that your friends are upwardly mobile ( financially ) so they can leave for a better quality life elsewhere, it would suck to be trapped here as a low income earner with no other option.