What should I prepare prior to her arrival?

Generally, I divided up my preparation into 5 distinct categories:

1. Items for the newborn
• This includes everything you can think of such as clothing items, toiletries, nursery items, feeding items, big ticket items (e.g. stroller, car seat, crib, etc.), and a whole lot more - you can easily go on the internet and find a list of items to prepare for newborns.
2. Items for the mother
• This would include nursing items (if you intend to breastfeed), sanitary and toiletry items (e.g. disposable underwear, maternity pads, dry shampoo if you are so inclined, etc), and anything else to make the mother's confinement period as comfortable as possible. 
3. Equipment for the kitchen
• If you're like me (a full-time working wife who under-utilizes her beautiful kitchen), then you would need to raid your mum's kitchen for some kitchen utility items for use during the confinement period. You would need a double-boiler pot, a steamer, a wok, plenty of pots of all sizes to boil water and herbs and soups (which are either simmering all day on the stove or cooling down around the kitchen), a kettle, an electric hot water vacuum flask, plenty of Tupperwares of all sizes and shapes, knives, mortar and pestle, etc. Basically, your kitchen must be equipped for full-fledged Chinese cooking for a month.
4. Fresh ingredients for cooking
• This is divided into fresh food you buy from the market, and herbs you buy from your local Chinese herbal shop / medical hall.
• Auntie Ah Tai would be able to advise on which vegetables and fish and meat would be suitable for her to cook for the mother's consumption on the first week - the mother's diet being dependent on whether she had a natural birth or a C-section. The father would need to do weekly shopping at the market to stock up the fridge.
• Your local Chinese herbal shop can advise you on which herbs should be purchased. I bought a 30-day confinement soups package from my local medical hall, along with other herbs for the red date tea (to be drunk daily by the mother as water), Brands' ready-made essence of chicken, muk yi, dong kuai, tong sam, kei chi, and other Chinese herbs to be added into dishes and soups.
5. Auntie Ah Tai's temporary living arrangements
• Like any other guest you invite to your home, you would need to prepare a place for the confinement lady to rest, sleep, bathe and put her clothes and other personal items.