nastra30

Awesome. 

And this exact scenario is outlined in the Adjudicator's Field Manual (the new Policy Manual isn't fully online yet, but this guidance still stands): https://www.uscis.gov/sites/default/files/document/policy-manual-afm/afm21-external.pdf 
 
Review automatic revocation on p. 68:
The grounds for automatic revocation are set forth in 8 CFR 205.1(a) . Officers should be familiar with each of the events spelled out in the regulation. Under each of these grounds, the revocation is automatic when the specified events occurs, regardless of whether USCIS is aware of its occurrence or not, and regardless of when (or even whether) USCIS provides notification of the revocation. For example, if an alien who is the beneficiary of an approved 2nd preference visa petition as the unmarried son or daughter of a lawful permanent resident marries before immigrating to the United States or adjusting status, the petition’s approval is revoked. It should be noted that although it is the event of the marriage which triggers the revocation, the revocation itself is as of the date of the petition’s approval (in automatic revocation proceedings, revocation upon notice is different). Furthermore, because the petition’s approval has been revoked, it does not become valid again if the marriage of the beneficiary is terminated through divorce or death of the beneficiary’s spouse. (However, if the marriage is annulled by a court of competent authority, the legal effect is that the marriage never occurred and therefore, neither did the revocation.) 

The law is not silent on this issue. The law for automatic revocation is in 8 CFR 205.1(a): https://www.ecfr.gov/current/title-8/chapter-I/subchapter-B/part-205/section-205.1
§ 205.1 Automatic revocation.
(a) Reasons for automatic revocation. The approval of a petition or self-petition made under section 204 of the Act and in accordance with part 204 of this chapter is revoked as of the date of approval:
 
(I) Upon the marriage of a person accorded status as a son or daughter of a lawful permanent resident alien under section 203(a)(2) of the Act.

Petition is void as soon he got married. Simple as that.

The next important step is marry within 90days upon arrival in the US.
Then with marriage certificate apply to adjust status using I-485.
Also recommended to file I-765, and I-131.
Read the VJ guides: 
 

The first case died as soon as he married, she can file for him again as soon as the divorce was completed.

INA 203(a)(2)(B) says that for the petition to be valid, your brother should be unmarried, which your brother satisfied in 2016. In addition to that, AFAIK, law is silent about what happens while waiting for visa. Since he is currently unmarried, I don't think there will be any problem with his interview. 

Yes, it's allowed by law if you so choose. How old is daughter?

Based on timelines you've provided, yes, petitioner can leave. Biometrics for I-130 is extremely extremely rare so don't worry about that. File online so you can get receipt pretty right away. Good luck.

Based on timelines you've provided, yes, petitioner can leave. Biometrics for I-130 is extremely extremely rare so don't worry about that. File online so you can get receipt pretty right away. Good luck.

It's not like @leignot is going to get an award for picking a harder 3 year rule route? With the same outcome (citizenship) what's the rationale for going 3 year rule route? It's not faster either.

If eligible for 5 year rule, it's not a brainer. 5 year rule wins: simpler,  doesn't involve reproving marriage, less evidence required.

Op had a combo interview for ROC and naturalization. They won't send you a 10 year card if they expect you to swear the oath.

Another trend is the subtle nudge to make people file online by making online filing fees less than paper filings. With the eventual goal of killing off those paper applications and making more forms available online.

I believe applicants of age 75+ years do not need to pay a biometric fee. Perhaps the without biometrics is in reference to this group.

No, N400 doesn't supersede I-751. They are still separate cases so essentially you will have two cases to get approved for. However, N400 will never get approved until I751 has been approved. Including a letter for combo is just a courtesy letter; they don't have to act on it. If you still wish to, you can still add it now as unsolicited.
Nonetheless, you may still get a combo regardless especially if your field office is known for doing that. Even if don't get a combo, at least you gotten the N400 rolling and dodged the April fee increases. Good luck.

Yes safe to travel. But if traveling with kids make sure dad is on board with them traveling unless you have full custody.

Just don't pay the NVC fees or submit documents.  You can delay the case indefinitely at NVC by contacting them at least once a year.

No, N400 doesn't supersede I-751. They are still separate cases so essentially you will have two cases to get approved for. However, N400 will never get approved until I751 has been approved. Including a letter for combo is just a courtesy letter; they don't have to act on it. If you still wish to, you can still add it now as unsolicited.
Nonetheless, you may still get a combo regardless especially if your field office is known for doing that. Even if don't get a combo, at least you gotten the N400 rolling and dodged the April fee increases. Good luck.

Ahh I see, wife is the derivative not the principal.

I don't think interviewing officer has that authority to determine abandonment in this case. It will become a court case at that point if op is willing to fight it. Also, the person can't just enter and naturalize; they'll have to meet a fresh set of residency and physical presence requirements.

As said above, nothing for you to do really. As the DoS website says "Note: Visa applicants must qualify on the basis of the applicant's residence and ties abroad, rather than assurances from U.S. family and friends. A letter of invitation or Affidavit of Support is not needed to apply for a visitor visa. If you choose to bring a letter of invitation or Affidavit of Support to your interview, please remember it is not one of the factors used in determining whether to issue or deny the visa."
 
Where is your sister from? Some countries are tougher than others, and the wait time for an interview varies hugely as well.

The gender mix adds a bit of extra complexity to the family’s decision.
The derivative children are still able to get visa with the father ( as born out of wedlock, if they are biological ) . They can enter to activate green card, stay long enough to apply for I-131 Re entry permit and go back to wait out mothers process .

It doesn't sound like he's ineligible for a visa. It's his 'wife' that is, as they're not legally married so she cannot get a visa as a derivative.

N-600. You can also first get him a US passport if he doesn't already have one.