since your husbands mother is an immigrant, she might of applied for citizenship, she would have first have to applied for temporary card, then permanent card, then she might have become a naturalized citizen. If this was the case then her records are kept in the national archives, where these type of documents are kept. thus, you must go to the national archives to obtain copies of these documents:temporary card, permanent card, and naturilization records(naturalization record is when they apply to become united states citizens citizens)so, go to the national archives. call your operator and get the address and the telephone number of your national archives in your state.