The Giving and Receiving Ceremony is practically the whole point of the trip -it IS the final adoption and can be cancelled if the officials are offended or upset in any way or get a wiff of American arrogance. A friend warned me that the officials almost cancelled hers because they did not think she was dressed fancy enough. Luckily, the officials in Binh Thuan Province were very understanding an very dear and seemed to appreciate both family's sincere intent to honor to Vietnam and it's people and raise the children knowing about their heritage.
I prepared, of course, by shopping! The traditional Vietnamese Dress http://en.wikipedia.org/wiki/Aodai is lovely and perhaps not so suited for a western woman "of a certain age" but my efforts seemed to be appreciated. Young girls ran to get me breakfast and people on the street smiled- everyone loved my Ao dia, it seemed except for a little group of street boys who threw themselves on the ground rolling and laughing when I walked by!
Here is the seamstress taking out the arms to accommodate a bit of movement. In Vietnam the Ao dai is considered standard dress. You see women riding scooters in them and at the airport women baggage handlers were wearing them. An interesting mix of modernism and tradition.