can you sue your girlfriend if your baby comes out messed up due to her smoking addiction?

I understand that smoking is a addiction. I don't smoke and my girlfriend is always talking about quitting. Even before she was pregnant she told me that she had quit smoking. I caught her outside with her friends smoking. She said she was only smoking a half of a cigarette. Her reasoning, because her friends were outside doing it. Well yesterday, I came from the library, and when I walked by the Shalom center. Part of a church. I saw a big puff of smoke come out of her mouth. She dropped the cigarette, put it underneath her feet as I walked on by. I was hot and burning mad. The only reason I didn't say anything right than and there, because I would have said some words I knew I wouldn't be able to take back. After walking around the corner to think, I came back, and she was still outside smoking. This time she didn't drop the cigarette but told me, I'm smoking again, but only I'm smoking a half of cigarette. You have to understand, I am trying. I really wanted to take the cigarette and shove it down her throat. But instead I walked off. I'm tired of hearing her excuses, and believe me, she has a reasoning for everything. I can't stand women to see a pregnant woman smokes. My mom did that to me and it pretty much messed me up as far as sporting events in school. In all fairness, Now this may sound harsh, but if my girlfriend wants to kill herself with the cigarettes, knock herself silly. But there is a little one inside of her that isn't given a choice. I already told her, if she continues to smoke and the baby comes out screwed up. I would take custody of the child and than sue her. Can I legally sue her if my baby comes out messed up because of her smoking?