It really depends on your state's laws. For example, in California, there is case law that supports free rent, company car, etc., as income. The citations are In re Marriage of Cheriton, (2001) 92 Cal.App.4th 269 (citing Stewart v. Gomez, supra, 47 Cal.App.4th at pp. 1754-1755 [reasonable value of rent-free housing is income]; In re Marriage of Schulze, (1997) 60 Cal.App.4th 519 [company car and parent-employers' rent subsidy constitute income].
Pursuant to tax law, the apartment complex can even report her free accommodations as taxable income to her. Generally, this is not reported on the W-2 because it is not income paid out; however, she may receive a 1099 form at the end of the year.
I would suggest requesting a copy of her tax records prior to the hearing.
I am a family law attorney.