I still can’t figure out why she would take him to a shooting range. Just sounds a bit extreme to be teaching those skills to a kid like this.
Do we know this for sure? That she did this?
No, we don’t know for sure that she took him to the shooting range. There were some quotes from people about the brothers at some younger age learning to shoot and those quotes got twisted around. One range owner is quoted a saying he didn’t know her or him and the FBI searched for them on the sign in sheets for way back in time and didn’t find them.