Why? Are you afraid her bag will be stolen out of baggage claim? Items inside pilfered? Mugged for the bag once she gets out of the airport terminal? SGN terminal baggage claim is quite OK, in my experience (I've never had problems going in or out of any VN airport)--it's not that big of an airport and in most of Asia, usually there are less theft problems of entire suitcases off the belt than in major US airports. And Vietnam itself is pretty safe place for foreigners except for, as you noted, petty crimes. I would guess the biggest threat to the bag and contents is by the SFO handlers--not in HKG and not in SGN. As always, no electronics or valuables or important medicines should be in checked luggage--she should keep those with her in the cabin. And despite what TSA tells you, I ALWAYS put locks on luggage and especially when flying international.