That should be fine. I should probably add that mentioning your role as a Deputy Head Girl could you in your academic reference, as it shows that you're fairly academically proficient, that you are responsible, that you've earned your teacher's admiration and/or trust, etc.
One suggestion I've seen is that you could split your "achievements" into character-based stuff that goes into your academic reference, and academic - related stuff that goes into your personal statement. That way, you can get to show how much you love the academia behind your subject (by, for example, getting work experience, participating in maths or chemistry competitions, or whatever), while complementing it with all the wishy-washy stuff that your teachers may wish to say about you (being hardworking, diligent, involved, trustworthy, etc)