Hey there!
I, in fact, am the youngest staff member on the PotterworldMC staff team. When first reading this thread title, I also agreed that the Jr. Prefect age requirement should be lowered to 13. However, it soon dawned on me that exactly a year ago (I just turned 14), I would have had trouble dealing with the themes that goes into moderation. I am now also a Jr. Prefect, and even with my young age, there are things I see that disturb me and cause me anxiety, causing me to have issues in day to day events. While I do agree that not all young people are immature, since I do believe I am mature, and in fact am very young, I do believe that the age requirement should stay the same. If you look on applications, I would say that the other positions on the staff team (which have a 13 year old age requirement) have that age requirement for a reason. I first joined the Potterworld staff team as a Seer, and that was the correct step for me. While it made my experience on Potterworld grow, I felt it also gave me that boost in maturity, and it gave me insight on to what sort of situations moderation deals with. From there, at first, I decided I didn't want to be a Jr. Prefect (for personal reasons). It took me 5 months before I decided to apply for moderation, when I felt I was truly ready. I'm going to stress that I know there are 13 year olds that are more mature than me still, but I definitely think that it's a large deal and a large decision to make overnight.
For these reasons, I also disagree that the age requirement should be lowered to 13. Thank you!