1)
Why did she say "Achi"?
1.
Malbim: You are my brother - each of us must be concerned for his or her sibling's honor!
2)
Why did she say "Lo Ya'aseh Chen b'Yisrael
1.
Malbim: She hinted that the action is like that of Shechem ben Chamor - "Nevalah Asah v'Yisrael" (Bereishis 34:7).
