The response indicates the amount of** cash support the student (and his/her spouse) received from a friend or relative, if** the student is a dependent student in 2015 and this support is not reported elsewhere on the application.
The amount should include any money paid on the student’s behalf by someone other than the student (and his/her spouse) for rent, utility bills, etc., while the student attends school, unless the person making these payments is the parent whose information is reported on this application.
Include money received from a parent or other person whose financial information is not reported on the application and that is not part of a legal child support agreement.
Note: This amount also includes any distributions to the student beneficiary from a 529 plan that is owned by someone other than the parents (in the case of a dependent student) or the student (such as grandparents, aunts, uncles, and non-custodial parents).
https://fafsa.ed.gov/fotw1617/help/faadef22.htm
Where it is going to get sticky is for g-ma to file children as dependents on her taxes, they should be living with g-ma 50% of the time and g-ma is providing 50% of support. IF g-ma is giving them money, purchasing their books, paying toward their school, then monies must go on the FAFSA.