Alumni letter of rec?

My teacher who is writing one of my letters is also a Duke alumni. Would it be beneficial if her to write an addition/different letter specific to Duke. I know sometimes alumni letters are not worth it because they can’t tell a lot about the person’s character. Due to the fact she is also my teacher would this be a situation where it could help? Thank you.

Sounds like a good idea. But how would you do this ? Upload two different letters to the common app?

What would the teacher say differently in the Duke specific letter?