Ames, you've proven beyond doubt that you are capable of anything. At a time when a good story brings us readers to read and enjoy those gems on offer from our writing pool, something like this emerges and reminds us that we have plenty of talent here on AI, and those of us who write, as well as read are blessed by people like you who move into new territory and this ficlet is a wonderful example.
I thought the letter form was perfectly natural, and expressed the perfect array of feeling, the anxiety of a woman worrying for her true love, her husband and friend. Penelope, and her persona is the perfect muse for this excellent Harry Potter story, James and Lilly, pairing, the way you use language is beautiful, the characters breathe through your hand, the images come alive and we are right there, feeling the pain and the relief and the uncertanty. Baby Harry is so cute too!
You did great, and keep going with your writing, it is always uplifting to see inkers that have been around a while come out with a new gem, and all of us are the luckier for this... thanks girl! <3