Dont arrest her. Feed her the bread and see how it works out. Make her eat it while under observation. She clearly intended to do harm. Let her face the direct consequences of her actions.
If she had shot a bullet at someone and it bounced back and hit her in the eye, killing her in the process- everyone would say it was fitting and move on. Why would we incarcerate temporarily a person who has no respect for human life and so brazenly and easily sought to end it. There's a reason why murderers are supposed to be executed. Same goes for those who attempt it.
Just like that idiot filming himself spraying raid roach killer(?) all over produce at Walmart. He got a couple years, should have been given life.
He was literally poisoning hundreds of people for a tiktok stunt.