If her only income is Social Security disability, she is not required to file a tax return at all unless she has a 1095A for marketplace health insurance. Does she have any other income like a pension, investment income, income from a retirement account?
And as for filing as Head of Household....no. She may have filed that way once upon a time, but in order to file HOH you have to claim a qualified dependent. It has nothing to do with actually owning a house. The "benefit" of filing HOH is a higher standard deduction. But that does not matter if she pays no tax now.
No----not rules about smoking etc. There are certain other kinds of disability income that would have rules that require her to show that she paid rent. There is no such rule for Social Security disability.
Neither one of you has any reason to enter anything about rent on a tax return.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
