I am potentially resigning from my position tomorrow to work for a company closer to home. Recently, a coworker of mine, who I won't really say I'm friends with, but am on good terms with, who completed the same developer internship that I did to become permanent, but for some reason, got placed in a different department, has been telling me that she wishes to do developer work again.
I initially told her in a hand-waving way that she must 'speak to the line manager about it', but now that I've got an offer from another company, and on the brink of leaving, want to make it up to her, and help her ease into my position during notice to take my place when I'm gone. She is always given fringe tasks to do in the advertising department, and most of the advertising team agrees that her talents are being wasted.
So in my resignation letter, which is going to be addressed to my line manager and all of HR, can I mention that there is someone within the company who I will train to take my place? I'm obviously not going to mention her name in the mail, but when my manager wants a face-to-face conversation about my resignation, I want to speak about it in more detail.