It may be possible for a 2 year old to pull the trigger once and with a lot of luck to hit someone BUT to hold onto a fired gun (the shock and sound for a 2 year old means drop it and run), then also hold on after the recoil (that firearm is going to jump and a 2 year old ain’t got any clue about gripping a firearm) and fire a other round also hitting him (means the kid is still pointing the firearm in pretty much the same for a follow up) … not buying it. Grandma is covering for someone.
This is what forensics are for.
I'll readily agree with you that what we get from the media is rarely, if ever, anything close to the full story.