There she sits, her hands are heldTight around her glassShe only needs to be aloneShe knows this mood will passTo realise that she was strongAnd he too weak to stayAnd to realise that she is better off this way
I would have done it differently, but this formatting highlights a structural contrast between "she was strong" and "he too weak." By itself, "he too weak" is just a phrase. The preceding "she was strong" sets up an instance of ellipsis, and the verb is merely implied ("he [was] too weak"). "He too weak" needs "she was strong" in order to make sense (formally speaking, at least). It can't stand on its own, and in a way, this dependence matches the person it describes.