Name Change

[munshi]

My mom currently has a 10 year B2 visa, and on her passport she has FNU as First Name and her real first name as the Last Name. She is a widow, and does not have a marriage certificate, but would now like to adopt my father's last name as hers. Does she have to go through the legal name change procedure, or can she somehow get some affidavits from our relatives saying that she was married to my father, and produce those affidavits to the Indian passport office to request a new booklet with the new last name? Also, would she be able to show those affidavits when she travels to the US to provide the justification/proof of name change? Please advise.

[immihelp]

Legal name change procedure.