Thank you for the feedback. I'm glad you've enjoyed Sofia's route after you were waiting so patiently for so long.
To answer your question, no, there is no instance once you get to the 'letter in the trunk' stage that she will come back. She has been too hurt by your previous behaviour.
There is a way to have her arrive to speak to you instead of sending a letter (you may have already seen it), but once you are at the letter stage, the letter you send (or not) will only influence your reaction at the embassy and the good ending.
Many thanks for playing