Dear M.,
As a former communication disorders and sciences major, my suggestion is to definitely take your daughter to a doctor. However, it may be best to take her to a specialist (ear nose and throat specialist). The ENT is an expert at diagnosing such infections, and if they determine your daughter has one, then he/she will prescribe a course of antibiotics that is location-specific, rather than whole-body. In most cases, a general pediatrician will prescribe a whole-body antiobiotic, which is not necessary since the whole body is not what is affected!
In terms of the smoking issue....I don't think it is EVER ok to smoke around children. I have to admit that I do feel strongly about this since I am a non-smoker, but exposure to second hand smoke is not good for ANY one regardless of age. While I understand that your boyfriend and his mother are smokers, they need to realize that they are joepardizing your daughter's health! I think smokers can be so selfish at times! My mom, who has breast cancer I might add, continues to smoke, which is obviously her personal choice, but when she attempts to smoke around my son, I have to put my foot down. She often thinks that going into a different room will reduce my son's exposure. NOT! The fumes can drift from room to room! If staying at your own home will help reduce your daughter's exposure to second-hand smoke, then by all means, stay there. Your daughter's health is what is most important. BTW, most ear infections (otitis media) are caused by stagnant fluid that accumulates in the ear. The reason doctors prescribe antibiotics is because they dry up that fluid so that the ear is restored to its healthy state. Good luck with taking your daughter to the doctor, and best wishes for a happy and healthy pregnancy!
D. D