1. Meet with your three-person team and develop a joint requirements analysis document with the best ideas from each person. Mark each major section with the author(s) names, or mark it as "jointly developed".
2. Make your decisions by consensus when possible. When agreement is not reached, vote on which way your document should go.
3. Pay particular attention to functional requirements, and try to identify ones that revolve around actual tasks/activities/interactions of users with the system.
4. Pay particular attention to the proposed educational activities, recalling that we are aiming at grades 4-8. Try to envision kid-friendly ways to convey the various curriculum subjects. It is OK to be somewhat selective about our scope, but not OK to say that the only activities our system will support are logins and reading screens of text.