Law School Addendum

I haven't finished undergrad yet but am wondering if I should write an addendum for Law School application. For context I expect my Final GPA to be around 3.2, my freshman spring-sophmore spring my mom faced health issues which required me to come home from school often and take care of her (4 hours away) some weekends I would miss class and this all took a toll on me. My junior and senior year grades are good 3.5> semesters. How should I go about this?