CnC for this piece:
that thingy in the top right is seriously LQ, i'd remove it with some careful clip masks with a soft brush (or delete the layer lol)
the umbrella above here head is slightly transparent, for me this is killing a lot of potential depth
i also find the lighting very off, for example that white circle below her head, it is very light but is positioned in a dark area (judging from light on the render) yet is not hining onto her face/body
the lightsource is well placed but its washed the colour out of the top right, i'd lower the opacity of it...
considering that, it still looks pleasing too the eyes, so overall, a good sig