Master Plan of the Young and Dying

Ben,

My first decision was that I wouldn't tell you until it was too late. It was a choice that would serve better for the both of us, I decided. I didn't want to spend my last few months of life being doted upon and worried about like some child. I am 23 years old. Plus, I knew Mom would just worry herself sick and I didn't want that. I knew you'd try to hard too make up for lost time and you'd regret ever getting that huge corporation job in NYC, while I went to school in St. Cloud and Mom stayed in Little Falls. I didn't want you to do that to yourself, Ben. At least, not yet.
I decided that if anyone should make up for lost time, it should be me. So, I started it. The Master Plan. Using each of the months of my remaining time here on Earth, I planned and prepared something for everyone. A situation, an event, a hidden item that only they could use. And now that you're reading this, I know you've found part of yours.
I planned for you to be the first. You're special. Everyone else will get their prize in a significantly short amount of time. You have to wait. You have to wait until you've helped everyone else, Ben.
In the package attached to this letter, you hold all the answers.
Please, don't be angry. I know you'll figure it out. I know you can help me.
Please, don't feel betrayed. I'm giving you a gift. I can only hope you will live an amazing life without me.

I love you, Benners.

Sarah.