Per IRS rules, the money they are giving you is not "rent" since you are not renting the property to them at fair market value. When a property is "rented" below FMV, it is considered personal use of the property.
The money you are receiving is expense-sharing and is not taxable income to you and not reportable on your tax return.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
