There are a lot of different things to love about this story. I really love this bit of description and interpretation. Really is a great definition of Thingol and Melian for me:

Since their marriage he had changed in appearance, taking on more of the look of a Maia to match his wife, his hair turning silver and his already lanky body growing taller. Melian knew the Valar and Maiar held great significance for Elu. He revered them she thought, perhaps too much. He had developed such an imperious attitude in his dealings with others, particularly the Noldor, that she disapproved but did not admonish him for it, preferring to let things take what she believed to be their predestined course.

You paint Melian in a tragic light. One that I am willing to buy. She is caught between her conviction of the futility of trying to outmaneuver an inexorable fate, but then when all of the destinies which she has foreseen work themselves out, she is lost in confusion that perhaps she might have intervened and changed something. Heavy stuff.

The last lines are killer ones--all that greatest boiling down to this for her?

She spent the rest of her time walking in the gardens surrounded by her birds and other small animals, ruminating on the past and on what might have been.