Help!

My sister has been taking vicodin off and on during her pregnancy. Freakishly our due dates are around the same time. She is 32 weeks and has taken quite a bit for the past 5 days and she's afraid that the baby will be addicted. Mind u these were not prescribed but she's been struggling with migraines and she's afraid to tell her doctor she took them. I don't know what to tell her to do. I am not happy with her at all and being a big sister I'm terrified too. Does anybody know if the baby will be addicted. She stopped taking them after 5 days. But she's still terrified. And advice would be appriciated. Ty moms!