What on earth would an open letter to parents have to do with this shooting?
Hey Michelle, we know how to raise our children, and we don't need you or anyone else in the government telling us how. This shooting has nothing to do with how we raise our children and everything to do with some nutcase going off the deep end.
If you want to do something, sweetie, then advocate for the loosening of unconstitutional gun laws so that every nutbag in the country knows that any given American might be carrying a gun and won't make such easy prey as an unarmed congresswoman.