Nope. The FAFSA only uses the parent (and the new spouse) the student lives with. CSS asks for info for ‘all’ the parents, but it then has a formula for using either only the parents (not step parents) or it considers that the money is supporting 2 households. FAFSA only considers the expenses of one household.
There isn’t a lot fair about it. I was a single parent with 2 kids in college. No other income or other people supporting us. I only got one ‘adult’ expense allowance like FICA considerations and the asset allowance for a single was about 1/4 that allowed for a married couple, even if only one parent had income. I had a household of 3, two in college and made the same as the guy I sat next to at work, but he had a wife and one kid (also a household of 3), but our allowance weren’t the same at all. My house for 3 people didn’t cost less, my utilities weren’t less, the food costs weren’t less.
Unfair, but that’s how it is.