What can help with this problem?

I am currently 8 weeks pregnant with my second baby. I live at home with my mom right now until the beginning of next year. She has this fireplace, she puts wood in it and it smells awful. Smoke gets in the house and it bothers me. This is the one of the causes of my morning sickness, that and the smell of grease. But how do I get her to eliminate the smell that comes from it? If it is helpful, she does not have a screen over her fireplace, not even a cover. Will getting a screen or the gl thing help to eliminate the smell? All suggestions are helpful.