Thank you!
So as long as I have a valid H1-b, we can just go to the port of entry and get their H4 and move?
-Correct. When they enter US, they can get the H4 I-94 at the port of entry using your H1 approval notice, their passports, your marriage certificate, and your kid's birth certificate.
No need to file with USCIS?
-No.