C.O.
Contact ALL credit reporting agencies and let them know that your social security numbers have been stolen and place a FRAUD ALERT on any and all social security numbers that have been compromised.
Contact your police department as well. Tell them what you told us. They may send a team out to check for finger prints - i don't know what they will do in your town...however, I would press charges against her...13 or no...she needs to have consequences for her actions.
Contact the Social Security Administration and let them know them all of SSNs that have been compromised...they can place a fraud alert on those social security numbers.
From this point forward...keep all rooms locked that she is not allowed in or simply no longer allow her over to the home...you can meet in public places..
also call your bank and ensure that your checking account has a possible fraud alert on it as well - as if she's clever enough to steal the tax returns, she might have taken an old check as well....that could lead to huge problems as well..
GOOD LUCK!!!