In a word no. Short of getting someone to fly to SA and carry it.
Any device with a Lion battery is considered dangerous goods and can only be accepted to go on a planes if properly packaged, usually only by the manufacturer in it's original shrink wrapped box. UPS and other couriers do check what is being shipped to ensure that dangerous goods aren't accidentally accepted. My local DHL want to see the contents of any box I ship before they apply a security seal. Even the local post office check to see if the contents of a parcel are safe to fly (ironic really as they send stuff from here to the UK by boat). So couriers are out.
Puzzled that your wife can't send a SIM card. That's wrong as I regularly buy SIM cards for travelling and these always arrive by mail or courier. I think that is a misunderstanding on the part of UPS in HK.
As an aside I was flying from LHR to HKG a few years back in the front of the plane when a "very important passenger" announced loudly to the cabin crew that he had left his phone in the lounge. The response was that if found it would be available for collection on his return. After saying (more loudly) he simply couldn't travel without it as it contained all his important meeting details etc and couldn't it be brought to the aircraft, or he wold have to get off. A groan from my fellow travellers as we all knew if he didf there would be the inevitable delay as his baggage was found and removed, and our collective experience knew that often this short delay on this early evening flight usual becomes a long one.
He was told that his phone if found couldn't travel (obvious security issues here) He was insistent that he wouldn't fly without it. Someone had been working behind the scenes whilst this was going on and he was then told but lounge staff were searching for it, and if found he could have the SIM but not the phone. This compromise was accepted and shortly afterwards a girl was spotted running down the jetway to deliver said SIM. I have always thought that this was service rendered (by BA) beyond what was required or indeed might reasonable be expected.