Dear Kristen,
It sometimes happens that very young children act out their resentment of a younger sibling by the kinds of aggressive behavior you describe. The priority, of course, has to be on protecting the younger child, and not permitting his sister to have access to him. It's up to the parents to be sure this occurs. There really is no excuse for any further episodes, if the parents are being vigilant.
In addition, to preventing physical contact, parents should definitely institute time out in the
faceFace pain of any aggressive episodes. If this is implemented correctly, it will be
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