finally VO, when a derivative who is following-to-join notifies the consulate that s/he is ready to apply for a visa, how long does it take to schedule an interview date? will s/he has to go through the NVC to schedule an interview date; thus a long waiting period, or is the date scheduled by the consulate? if scheduled by the consulate, what's the estimated waiting period? thanks

Thank you VO for the detailed explanation/clarification. I'm sure your response answers many questions in other readers' mind.
Stay well and have a nice week.

again thank you VO.
going back to your earlier response "following-to-join applicants may derive immigration benefits only if: 1. The spouse or children were acquired before the principal applicant's admission into the United States..etc"

1. what happens in a situation where the derivative was not included in the original approved petition on which the principal migrated to the usa (but derivative name was filled in form DS-260 as spouse/child of principal applicant). does derivative need to complete form I-824 or does s/he just need to email lagosiv@state.gov asking for name to be included, even though the principal's visa has been issued and principal is already in the usa? Wont the case be considered closed once the principal has been issued a visa?

2. if the derivative was not included in the original approved petition but was later added to it by emailing lagosiv@state.gov, however derivative did not attend visa interview with principal because s/he wishes to follow-to-join, will s/he need to fill form I-824 or s/he just need to schedule an appointment and submit form DS-260 with required documents?

thank you

many thanks for the detailed response VO.
does derivative need to complete form I-824 when s/he is ready to apply for visa or s/he just need to schedule a visa appointment?
thanks

dear VO, pls what's the timeframe a derivative is expected to apply for his/her visa to join the principal applicant whose visa was granted. derivative was part of an approved I-130 on which principal applicant got their visa, but derivative didn't attend interview with principal applicant because he/she would like to follow to join. thanks

Dear VO,
I'm a beneficiary of an F2b (family-based immigrant visa petition) already scheduled for a visa interview in July 2015. Now that I have a child, I'm wondering if my child does qualify to apply for an immigrant visa with me as a dependant, even though she wasn't included in the original petition, as she was unborn at the time. Please bear in mind, I'm still single/unmarried.
1a. If she does qualify to apply. How do I add her name to the petition since my case is currently with the U.S. Consular post in Lagos? And what are the documents I need to provide?
1b. Does she definitely need to apply for an immigrant visa at the same time with me? If the answer is No, then...
1c. What's the timeframe allowed for her to apply for a visa incase she is to join me later based on same petition?
Will truly appreciate your advice and quick response.
Thanks