Thanks for your response, I was thinking it to be straightforward, but seems not that easy to get CBRA, I used to have all the bank statements, paystubs for last 15 yrs but had thrown away most of the stuff becaue I thought i dont need them anymore and the old stubs used to have SSN on them. I the CBRA doesnt go through, my wife has temporary green card and we have filed I 751 to remove the condition. Can she bring the baby based on her extension? Also does the Airline allow the baby to board the plane with out US Visa? I saw ETSA to borad teh flight, what does ETSA mean?
You should definitely try to get CBRA first and see what happens.
The consular officers processing CBRA requests and conducting the CBRA-related interviews have fairly wide discretion and there is a significant degree of variability in what they actually require in terms of documenting physical presence. A great deal depends on the particular consular post and on your luck with a particular consular officer.
A friend of mine had to get a CBRA for his daughter in Australia about 3 years ago. He was a natural born U.S. citizen but his wife was an Australian citizen (not even an LPR). After their daughter was born in Melbourne, he applied for a CBRA there. He says that the ONLY thing he had to do regarding his physical presence was to fill out a sworn affidavit listing the dates of his entry to/exits from the U.S. He says that the consular officer did not ask for any additional supporting documents, although during the interview my friend did have to explain his background (where he was born, went to school, college etc).
On the other hand, there are quite a few stories of the opposite kind, where the consular officer requires a lot of documentation about physical presence and is very nit-picky about it.
The relevant State Department document says this:
"When doubt exists that the parent’s physical presence in the United States is sufficient to transmit citizenship, documentary evidence of the claimed physical presence is required;"
See p. 19 at
http://www.state.gov/documents/organization/86801.pdf
In preparation to applying for a CBRA you could ask the CBP for a record of your entries to/exits from the U.S.
This can be doing by filing a FOIA request with CBP, see the instructions at
https://help.cbp.gov/app/answers/de...-of-my-travel-in-and-out-of-the-united-states
You should also try to get school records if you went to school and then to college in the U.S.
Also, you could simply ask as many people as you can who knew you back in the U.S. to provide notarized statements affirming that they personally knew you during such and such period and that you lived in such and such place at the time.
Basically, I would not give up on CBRA without trying first.