Family Based Greencard

Hi guys, can someone please advise me on what to do on my case. Im currently a LPR and wife has been scheduled for an interview on Jan 25 but she had a baby a couple of weeks before her date was scheduled. I understand I need to update my documents but I've called both the NVC and the embassy for assistance but no help. The embassy customer service rep asked to send a mail which I did twice but still haven't heard from there yet. Nvc also said since the case is with the embassy they can't do anything about it not but its up to the embassy to make any adjustment. Spoke with a couple of friends and they said the embassy will add the baby once my wife show up with birth certificate and passport if baby. Some1 also added I should fill a new DS-260 form and a new i864 form for her before the interview. That's part one.
Part 2, I will become a citizen before my wife goes for the interview so called NVC if they will need the documents ones I become a citizen and the rep told me, when I become a citizen, then my wife may have to wait while I file another I-130 for my baby to go through almost the same hell of wait my wife went through till the baby also gets approved before they come. I really don't know how true this is but if she's right, I will rather chose not to tell them till they both get here as a LPR then adjust my baby's status. Can anyone advise me on this so I know what to do since I still have enough time to make changes.
Thanks
Sonique