So, 2 posters are 'recommending' eliminating the hands/hand usage. I don't recommend the 'Bat drag, hand eliminator buster'.Bat drag buster from BR..
This pic is from last year, but this has always been a problem for my DD. No matter how many times I say you are barring your lead arm, she is unable to correct it. Are there any good drills to prevent lead arm from barring.
I am not recommending eliminating the hands. The bat drag buster helps to teach how the elbows work in unison (think Howie Kendricks). Keeps elbow apart instead of them coming to close to each other as in photo provided by OP. This is a weak position and all she can do is drag the barrel around and flick or frail at the ball with little power. Also her lead arm laying across her chest is another weak position that the drag buster will help eliminate. With that being said, there are some mlb players that arm bar (probably not intentionally) to a certain degree and lay lead arm across chest. Usually power hitting lefties guess players with long swings. Griffey