@pickly2023 - let's go all the way back and define what is a rental and what is personal use of a home. The IRS separates the world between the two - there is no overlap based on their definitions.
here is the definition of a "personal use" and therefore anything else is rental use.
Note that when ANYONE uses your home and pays less than the fair market price to live there, that is a personal use day and not a rental day. And as such, any income received from a personal use day is not reported as taxable income.
As long as the sum of the gifts is less than the fair market rental of the home you are permitting your mother to reside in, there can't be an arguement. It's not 'rent' to begin with.
https://www.irs.gov/pub/irs-pdf/p527.pdf
page 18:
What is a day of personal use? A day of personal use of a dwelling unit is any day that the unit is used by any of the following persons.
1. You or any other person who owns an interest in it, unless you rent it to another
owner as their main home under a shared equity financing agreement (defined later).
However, see Days used as a main home before or after renting, later.
2. A member of your family or a member of the family of any other person who owns
an interest in it,unless the family member uses the dwelling unit as their main home
and pays a fair rental price. Family includes only your spouse, siblings, half siblings, ancestors (parents, grandparents, etc.), and lineal descendants (children, grandchildren, etc.).
3. Anyone under an arrangement that lets you use some other dwelling unit.
4. Anyone at less than a fair rental price
