I actually really like her design. A lot of artists tend to exagerate her feminine features compared to what we see in the game (not blaming it, I completely understand, feminine features are pretty), but I think it kinda contradict the design itself.

In many cultures, wide hips and big breasts are a symbol of life and abundance, and I think FromSoftware designed her specifically to not have those to emphasize the deadly aspect of her character, so I tried to not exagerate them.

Source: https://www.reddit.com/r/Eldenring/comments/ufy5e9/i_painted_malenia_blade_of_miquella/i6w96h6/

The hardest details to paint were Millicent's sisters, because they all have different hairstyles, eyepatches and weapons (halo scythe, treespear, double flowing curved swords, and blade of calling) . So I had to find pictures of all of them to match every detail, it was a lot of fun.

Source: https://www.reddit.com/r/Eldenring/comments/ufy5e9/i_painted_malenia_blade_of_miquella/i6wb69d/