Financial Aid Effect of Sibling in College

i really dont mean to hijack, but just thought of this as reading this thread --if kid #1 is in grad school and kid #2 is going to public FAFSA school undergrad – will undergrad kid have a lower EFC? does grad school for kid #1 lower the federal EFC of kid #2? (just thinking about subsidized loans opportunity). thanks *and really didnt mean to side track!