Here's something to read over the next week. Professor Hartman replied to my question about adolescent participation in research. She agrees with me that the issue is murky, but when in doubt err on the side of "yes" (try and get parent and adolescent informed consent). At least have the informant speak to his/her parent, explain the project, and go from there.
The risks are minimal, and you are not professional researchers, and are engaged in classroom exercises. Nevertheless...let's try and educate parents as well as informants, and really explain the nature of class to them---and above all try and get consent from both parties.
Let me know what happens.
Below is the URL of a long article (2006, Vol. 4, Issue 1) by Professor Hartman on this issue: