Which city? I spend time in both Shanghai and Beijing and have a few specific tips for both if need be.
Mobiles – will uk iPhones work for texting home?
Yes, but I would stick with email over wifi for simple cost reasons. Also, just using email is easier than text when abroad. (Apart from da yoot, who texts anyway?)
Wifi – available in most bigger hotels? For skypeing.
Yes, in almost every “Westerner friendly” hotel. I ran Skype through a UK VPN, but I gather there may be some issues with Skype in China overall.
Dosh – credit cards ok most places and for cash withdrawals?
Major cards (Visa/Amex) are fine everywhere. Cash machines abound.
Some other stuff;
Don’t tip. Ever. Tipping is a no no in China.
When she checks in to her hotel, get her to take a business card and ask the reception to write the word “Taxi” in Chinese on the back, and keep it with her. If she gets stuck, point to the back, then get in cab and point to the front.
China is safe, amazingly so, but also very, very alien. It’s so different to anywhere else. An amazing mixture of fascination and revulsion. I love going there.