Is the 1/3 owner who lives in my two-family rental property considered a tenant?

I own 2/3 of a two-family house.
My family member owns 1/3 and lives in one of the units. She pays me a monthly amount of money that is far below market rental rates. I pay for all expenses for the house, including mortgage, taxes, insurance, maintenance, and repairs.
Should I include her contributions as rent payments? Also, can I claim 100% of the available deductions despite her 1/3 ownership?