Here is what I have done in that regard.
I used worksheet for determining support, publication 501.
On page 20 of 501, left-hand column, under Fair rental value defined, second paragraph, I am providing the "entire dwelling" because she has full use of my home, even though she is renting one of the bedrooms in my two-bedroom home. It is just her and I in the home.
So, on line 6b of the worksheet, I have entered Fair rental value of my home which then ends up divided in half on line 12. Or, a 50-50 split between her and me given that we both use the entire home.
So, that is my reasoning based on my reading of the paragraph. I hope that is correct.
