Hi. I'm currently a Year 4 student and I am at the quest where you need to convince Bill Weasley to..

Hi. I'm currently a Year 4 student and I am at the quest where you need to convince Bill Weasley to help you enter the Forbidden Forest. The attributes needed are: 18 Courage, 18 Empathy and 19 Knowledge. My current attributes are: 18 Courage, 18 Empathy, but 18 Knowledge. My Knowledge isnt enough to earn 3 stars. The problem is: I completed the classes and earned a few Knowledge points, but it still is not enough to reach 19. I cant buy clothes or pet looks because I dont have enough diamonds or money. I dont know what else to do to earn more Knowledge points. Please help.