Where do I add rent income from renting out a room in my home?

It depends.  Are you renting this room to her at a Fair Market Value or is she living with you and just helping out with the bills?

If she is just living with you and helping out with the bills and you are not renting her this room at a Fair Market Value, then you would not enter this as income on your return as it would not be taxable income.  

If you are renting this room to her at Fair Market Value, then you would enter this as Schedule E Rental income using TurboTax Premium or TurboTax Premier. This income will go in the rental section.  You can use the search bar and type in Rental Income, then Jump To.  You would then also be able to deduct prorated expenses, based on the portion of the house that she is using.  If it is just you and her there and she has full access to the house, then you would be able to deduct half of the expenses such as property insurance, mortgage interest, maintenance, etc. 

Where do I enter income and expenses from a rental property?

Rental Real Estate and Taxes