The background looks fine to me! The pose could use some work by making them feel a bit more free, try loosening the pose they are in. It adds expression even if she doesn't show it XD.
#Background, posing, and composition
vapid lagoon
slate dock
the fire look flaat so it make it look hella out of place
obtuse moss
hi.
The background is fine. for the sun, however, i reccomend looking at some references at sunrays. ex: https://www.azernews.az/media/pictures/Sun-Rays.jpg
this kind of effect can be done with an air brush. don't overthink it.
