One of her son is in China, and listed as derivative chidren.
1. Is it hard to DIY immigration visa for her son?
-Yes. She just needs to file I-824 for her son to apply for immigrant visa in China if her son is less than 21 years old. But her son cannot apply for the immigrant visa until she gets the green card. USCIS will not approve the I-824 until she gets her green card even if she files I-824 now.
2. The I-360 approval notice has not moved to NVC. I should first file I-824 to ask VSC to forwards to NVC, correct?
-Correct.
Thank you!