I think that all pregnant women are told not to smoke and anyone who says they didn't know it was harmful (to them or the baby) is either a liar or a moron.
That said, do you have any symptoms such as asthma or recurrent bronchitis or anything?
As far as your mom and smoking, you have to understand that it is really difficult for some people to quit smoking. You do not have to deal with her smoking around you, though. If she smokes in the house, leave the room when she lights up. Open a window. Ask her to step outside if it's warm enough. She'll get the picture.
My father smoked for the first fifteen or so years of my life, I think, but never in the house. He never smoked around me. I don't even recall him smoking while we were in the car together. And this was before we "knew" about lung cancer and second-hand smoke and crap.
Bottom line: you're old enough to get away, so just do not be around your mother when she smokes.