If she fraudulently obtained a new number, or is fraudulently using someone else's number and claiming it's hers, then yes, criminal identity theft may be occurring. The social security fraud hotline number is 1-800-269-0271.
There ARE, however, valid reasons why a person can be issued a new number, and often those situations stem from peripheral circumstances that seem to go hand in hand with financial difficulties. For example, if she had been in an abusive marriage, which are well known to include financial strangulation as part of the relationship structure, she could be issued a new number as part of an assistance program. See:
http://www.ssa.gov/pressoffice/domestic_fact.html
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While pointers can be helpful, ultimately the number one lesson in any legal action is: don't take legal advice from books, family, friends, co-workers, police officers, grocery clerks, web sites, or people on legal message boards. The only person who can give YOU legal advice is YOUR attorney.
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