score:5
Abraham Lincoln's birth mother, Nancy Lincoln, died when Abraham was 9 of either milk sickness or possibly consumption. Milk sickness is from drinking milk contaminated with the poison tremetol by the cows eating snakeroot. Two other people on the Lincoln's property also died of milk sickness. I can find no suggestion of foul play.
After Nancy died his father Thomas Lincoln married Sarah Bush Lincoln. She lived until 1869 outliving both Thomas and Abraham.
I also cannot find mention of Abraham shooting anyone, in the eye or otherwise. It is possible he shot someone during his stint as a Captain during the Black Hawk War, but that would be 20 years before his father died.