They will know of all her legal entries.....and I would expect some serious questions about the length of stays and how she legally re-entered with overstays. An overstay will immediately void an existing B2.....and getting another B2 with previous overstays is difficult. I would not be surprised if they look for misrepresentation of some kind. She might even need a waiver.
Which entry did the attorney omit? The 12 year stay?
I wouldn't worry about it. I don't see any requirement to have a strong social media profile. Just be truthful and give them what they want. The mental gymnastics during the immigration process can bring on anxiety. Just stay busy and keep learning the process and forms. Good luck.
Exactly what fees are you trying to pay? For an immigrant visa (CR-1), that would be the NVC processing fee and the Affidavit of Support fee....which are not applicable for K-1 cases.
For a K-1? What checklist? There is nothing to submit to NVC for a K-1. For a K-1, NVC simply assigns a DOS case number, then forwards the case to the consulate.