This is very beautifully-made! I love the colors and overall serene feel of the piece. I do sense some sadness coming from the character, however. I wonder if Dia is okay..?
Also, since crit is encouraged here on NG - I'd say her head is just slightly too big for her body, but only by a little. Disregard that if you were going for a mildly toony look.
My only other suggestion involves that the artwork piece cuts off too suddenly at the bottom. I keep thinking it has not finished loading yet. The composition feels cramped and awkward there, with her feet being cut off right at the edge as it is currently.
Thanks for sharing this lovely piece, and hope this helps for future projects 👌 I still gave this image the max rating because my suggestions are just minor stuff tbh. Stunning. 💖