Hello PP90210,
Since you have such limited space in your application to provide valuable information about yourself, I often suggest that recommenders not duplicate information that was already explained in detail in an essay or written about by another recommender. You want the person reading your application to "get to know you" by the information presented in your application so having a recommender use a different example presents additional insights into who you are as a person. However, if there is something that you feel is extremely significant then it's OK to write about it in your essay and also have a recommender allude to it in his/her recommendation. Hopefully what your recommender writes about aligns with what's in your essay but also adds some new information that wasn't covered in your essay. It's OK for some examples to be highlighted in multiple places in your application but hopefully in each instant there is something unique that adds value to what was already covered somewhere else.
Good luck!
Regards,
Dina Glasofer