Dear arkygal,
You can flie a joint return, but then you should also ask for allocation of your refunds.
You can read about innocent/injured spouse allocation at this site: http://www.irs.gov/pub/irs-pdf/f1040.pdf
Since Arkansas is not a community property state, and this is a debt that occured befor marriage, you will likely be able to successfully get the allocation.
Else you would need to file seperate returns.
Tax Preparer
GPHR Cert; U.S. Treasury Tax Advocacy Panel appointee