Tufts "Optional" Essay

I posted this on the Tufts board too, but since I want to finish my app tonight, I figured I might get responses more quickly here.

Anyway, I’m applying RD to Tufts and I’m a little confused about the optional essay-

The directions say:<br>

  1. Describe the environment in which you grew up and how it shaped your personal goals.
  2. Offer an editorial on a topic of your choice.
  3. There are times when applicants wish to provide additional information about their candidacy but the opportunity to do so is not addressed in any of the essay topics. Please use the optional essay as an invitation to do so.

My question is, if I have a really good essay about my Grandma that I wrote for another college, can I use it here under prompt #3? Or is #3 meant for applicants who want to explain a really bad grade, for example, or something else off about their application?

Thanks!