@thumper1 I edited my original post a bit after your reply. Older daughter goes to Grinnell, which does meet full need. I ran their NPC and it offers a $17K grant when I note a sibling in college and $0 without a sibling in college. Considering her merit aid is already greater than the $17K, she most likely would get nothing extra due to her younger sister being in college, right?
It sounds like, especially with it only being a 1 year overlap, I really should put no stock in this when trying to ascertain whether a school is within our budget or not and if we get some aid in year one, that’s just a nice surprise.