Although I understand that the 2 mice per week would be horribly underfeeding a sub or fully adult boa, lostkauze did not say what age the boa was at all. If this is only a juvie then the 2 mice per week is perfectly fine. This is more than adequate for a snake that is small. Even at 2 mice per week the boa will grow at a good rate and be a nice healthy adult if the food is kept proportional.
I would only hope that this biology teacher stated she was only feeding it two mice per week as opposed to feeding it every 3 - 4 days hoping to powerfeed it and have it grow into a monstrosity.
The only thing that worries me is that lostkauze stated she said she only feeds it enough to keep it alive. I hope that was a misunderstood comment.
Lostkauze- feel free to give your biology teacher the URL for Fauna so that she can find out just how damaging this feeding habit could be to the animal if, in fact, it is older than a juvenile. You can also give her my email address and I'd gladly explain to her how much damage she could do by under feeding.
I'm also sending you a PM with a link that you might want to print out and give to her.
If you'd really like to bring it to her attention and make the point stand out, hope for a chance where you can make a report or presentation at some point through the year and write or talk about how some people put the lives and health of the animals on the line because they are regarded as "just animals".