Nga&John

Please don't post wrong info to mislead everyone.

http://www.visajourney.com/content/i130guide2

So what's your question? He doesn't have record then he needs to go to a civil surgeon to have vaccination assessment filled. Locate your civil surgeon here:
https://egov.uscis.gov/crisgwi/go?action=offices.type&OfficeLocator.office_type=CIV

This info is completely wrong if OP did get married within 90 days. AOS is not required within 90 days.
No exact answer until we know if OP got married within 90 days.

The sole purpose of tourist visa interview is to prove:
1. Ties to home country (nope 1 as above comments contribute)
2. No intention to immigrate to US on non-immigrant visa, and will return when I-94 is over (nope 2 when she is waiting for her IMMIGRANT petition)
3. Have enough money to travel by HERSELF and on her OWN money (nope 3 when you want to pay for her expenses)
You don't accept reality so there is no point asking around. There is no argument of common-sense (as you explained in many "why would") between your spouse and US consulate, they play by the book and she can't persuade them with reasonable answers, there is no visa. Very simple yet straightforward as you know about US government system, there is no way around like Vietnam or China Governments. Only way to find out is that she takes the interview and we will wait for her result. Cross fingers for her.

OP has no idea how backlogged USCIS centers are now. Immigration is a challenge of patience.

It is your USCIS number on your Green Card

Yes you can have it sent again.
https://egov.uscis.gov/e-request/displayNDNForm.do;jsessionid=bacjlfTCIQ-Oy78tt-PDu?entryPoint=init&sroPageType=ndn

Card will come like a week, no need to stamp

The guest house, what will you do with that once you, your wife, and child move to the US? Can you see how that is not much of a tie?
Your wife has a USC husband and child, no income of her own in Vietnam, and you show 'technically no income' either. I think you should certainly apply but with two denials and very little ties to Vietnam, as of right now I would expect another denial.
good luck

Not for the B2.
B2 should be pretty much routine if you're residing overseas long-term together with your wife. Will be 99% decided before the interview even takes place based solely on the DS-160 contents.

To summarise:
Your wife has a USC Husband and child.
No job
Has had an Immigrant Petition filed for.
2 prior non immigrant visa's denied.
How have her ties and need to return changed?

1 vote for Nope

They check the income based almost on most recent tax return. So basically, if your spouse most recent tax return (2013) doesn't reflect poverty guideline, you still need a joint sponsor. Good luck.

NONE when you are USC by birth.

Do you know how many immigration laws have been passed from 1994 - 2014? Especially after 9/11 incident? Could you tell us if someone grinds your rears? Because I realize there has been no comments with "illegal-immigrant" hatred in this thread so far.

Ditto to Nancy, no offend given but you need to work on communal evidences like banks, bills, and insurances. We are talking about immigration laws, not showing how you love each other with love poems and FB chat.
If you don't have much, they will understand because you're new married couple. But nothing at all... Good luck.

All secondary evidences, you need commingling finances, banks lease bills insurance... Pictures, poems, facebook? I don't think so. If you don't have any means to build a family, how to live? Asking pocket money from mom?

The answer is NO! You will not find a single information about the USCIS case.

I don't encourage concerns filled with hatred.

Usually the OP and friend are the same person.

USA recognizes marriages in other countries. If she was married when she filed for the tourist visa and claimed to be single, she committed fraud by lying to the CO and putting false information on the visa application. There is no checking to see if you're already married when you apply for a marriage license in the USA, but it is illegal to marry another person before first terminating your current marriage. If she married the same person again with a license, it really has no affect other than to muddy the waters on the original date of the marriage because now there is two marriage certificates, but legally the earliest would take precedence.

I get the feeling they didn't understand that their marriage in her home country was accepted here. A fairly common misconception with people from many countries.

Even with a waiver, his chance to obtain a tourist visa is slim for controlled substances.

Please find another joint sponsor. Explanation letter will not help, if you cannot provide them with what they need, they will deny you case eventually and you will end up losing your filing fee.