I searched this thread in VJ. Some people have translated / certified translation of their birth certificate.
But the statement below makes no such reference. Futher I am astounded that a consulate office would be so inept as to need a BC translated. Anyone submitted a VN certificate without translation. Thanks Andrew

How can I obtain for my birth certificate? In case, I cannot obtain my birth certificate, what can I do?
Individuals born in Vietnam who need new copies of their Vietnamese birth certificates need to contact the office of the People's Committee of the district where they were born: the district where their mother was then resident according to her Ho Khau. The district People's Committee can issue certified copies of a birth certificate (Ban Sao) based on their records of the original birth certificate. Alternatively, the office may provide an Extract (Trich Luc) of the information in the birth record on file in their office

Andrew and Thuy,

She can obtain her Certified BC or Ban Sao in HCM City's UBND (Cityhall).
She can have her BC translated by "So Tu Phap" located on Pastuer Street, on the corner of Pastuer and Nguyen Du's street I think...

Here is why even if the consulate doesn't need to see (which they do) Thuy's BC in English, you will need it for your AOS (Adjustment of Status) later when she is here in the States. It's easy, cheap and "official" document to have! Ask Thuy to have a few copies of her BC translated, sealed and certified by "So Tu Phap" for later use!

Good luck! If you try to make sense everything HCMC does, you'll go coo-coo! I know I did, then VJ straighten me out! hahaha

Good Advice, thanks for making some sense out of it ! and for letting me know a place where it is conveniantly done.