♛Do the thing! Why not write to her? If you’re so close with your cousin, I can tell you that visits and letters can mean the world to someone who is otherwise cut off from it, whether by their own choice or not.

Perhaps what she did was in fact “okay” given her circumstances at the time. Could have been self-defense, or defense of someone who needed it. You might consider drawing out more of the facts in your letters with her. 

Whether she’s scary or not, and whatever her level of guilt, if you care about her, keep the connection. You can always stop when you have more information.