When you achieve Awakening, it's strange that you don't receive anything to serve as a memento of your relationship, therefore this will provide something for the Warden Commanders who dated Alistair but didn't make him king.

By installing the mod, entering runscript zz give letter into the game's console, and pressing Enter, you can add the letter. As a result, a codex entry will be made under notes. There's nothing origin or gender-specific in the letter so it works for all wardens.

Please be aware that this will not be compatible with any version of The Awakening Letter from King Alistair because it refers to the same codex entry. Make sure there is only one letter mod in your override folder before starting Awakening; else, it won't function.