Hello Karen! You didn't mention any time frame, but the rule is: a woman and/or child became naturalized when the immigrant husband/father was naturalized. I have seen on the 1920 census where the woman hadn't even come to the U.S. yet and was naturalized by the husband's naturalization. And, no, she wouldn't have had to sign anything that would indicate when she arrived. Depending on your time frame, you might be able to check the husband's papers to get info on her immigration. Here's an interesting website that gives some info on naturalization: http://www.genealogy.com/31_donna.html?Welcome=986088821 Hope this helps! Anna in MN