IRS reg 1.163.1 allows her as the equitable owner to deduct the interest even though she's not on the mortgage. In Turbotax she would use the Mortgage Interest part (under "Your Home" on the Deductions and Credits tab). As she goes through answering the questions there's one about her being on the 1098 to which she'll answer no. she'll need to provide your name and the full address that's on the 1098 that you'll get.
deducting the mortgage interest will only benefit her if that deduction with other schedule A deductions exceeds her standard deduction.
