HOW DO I GET HER ALONE? please answer?

My school has about 5000 gallons of aquariums, and after school a group takes care of them. However, I do it in my spare time, and have become the self appointed fish nut of the school. Well, she likes fish almost as much as I do, and now I think I know what else she likes, ME (she asked me if i have a girlfriend for christs sake!) . and, I think she is super cute and really wanna ask her out. However, in the new session of the program im in, there are abut 20 new people, and at any given point, 5-10 are following me around annoying me. and, 3 freinds of hers joined, and now I cant talk to her alone. But, I need to, otherwise ill never get anywhere. Also, understnad that shes in 6th grade but im in 8th grade, so if im wrong about this, I get a creepy reputation. However, I'm pretty sure im right. what can I do?