I think it is two fold.
1st, she is a pretty girl who runs around with many men. Enough to cause aggro between different suitors. I think that the first time around there is emphasis on that she is pretty enough to kill for, and, I think the narrator has killed 'for' her, that's why if he told you you would say you did not know what you know.
2nd, is obviously regarding having had abortions, but has kept some of her babies? Maybe the Narrator suffered from her having an abortion.
Can't see much else.