Legacy question

My DD2 is considering applying ED to Cornell. She wants to study fashion merchandising in the college of Human Ecology.
My DD1 is a junior, studying Pam in the college of Human Ecology. Would this count as legacy? The common app asks if you have family members who have attended and their graduation dates but it only lists parents and grandparents. Should she mention it somewhere and would it help her application?

She would not be considered as a legacy because Cornell is only considering parents and grandparents. Where she could mention her sister is in the “why Cornell” essay.