If she only lived with you for 7 months, there's a chance you didn't provide more than half her support for the entire year.
The IRS has a worksheet that can be used to help with the support calculation. See: http://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf
The support value of the home, provided by the taxpayer, is the fair market rental value of the home plus utilities & other expenses divided by the number of occupants.
