I think I'd find a way to make the portrait one a little bigger, and arrange the three others around it. The pictures all look good, but the arrangement isn't too attention grabbing to me.

Maybe top left is for the portrait (or even the color one, if you can change the sizes enough.

You can frame it with the color picture to the right of the portrait, lightning with her back to us below the portrait, and lightning/captain morgan in the diagonal bottom right.

Would there be a way to give the back ground an aged paper look, since she's a pirate, without messing with the quality of the drawings? Maybe with random treasure map themes in the background. Y'know, the "X", the fancy compass, some sea or waves, stuff like that.

Something that looks like old da Vinci sketch work, or maybe Darwin's sketch work.

Just throwing out ideas.