From:
http://kidshealth.org/parent/infecti...icken_pox.html
Pregnant women, as well as people with diseases or problems with their immune system, should not be near a person with chickenpox. If a pregnant woman who hasn't had chickenpox in the past contracts it (especially before 20 weeks), the fetus is at risk for birth defects.
From a quick read, I think it is a very slim chance you can contract it from her, but there is always a chance. If the germs get on you, that could be a porblem.
And I am not saying to stay away from her, but there is no need to go kissing her and engaing in body contact with your teacher. Isn't the job of a teacher, to teach?