General Questions

1. She could blame Stiles for her mother's suicide.
2. Try asking her about him.
3. But you'd better do it either before she sees the corpse or after she admits her part in Linder's plan.
4. She doesn't really blame Stiles.
5. Try asking Phong about the suicide. Or try asking Monica about her mother or her father or the affair.
6. Any of these will establish Monica's motive.
7. Monica's motive is that she blames Linder for her mother's death.