I heard in the name of Rav Chaim Shmuelevitz zt’l that when you hurt another Jew it’s like putting your hand in fire. If you see someone’s wallet fall into the fire and you stick your hand in the fire to save the wallet from burning up – what are you going to say “I had good intentions, why did my hand burn”?
So too, Penina had good intentions, but still she hurt Chana very badly. Every Yom Tov when you’re supposed to be happy, Chana had to hear Penina’s shtuchs and farshter her whole Yom Tov – so Penina had to pay the price.