Cosigning for her apartment lease does NOT count as support you provided. Cosigning the student loan DOES count as support you provided. Scholarships and the the expenses they paid are ignored (left out of the support calculation).
At $26,000 income, it's unlikely that she didn't provide more tan half her own support. Unless her income went into savings. Do not count scholarships as her income.
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 parent, is the fair market rental value of the home plus utilities & other expenses divided by the number of occupants.
