The shape of the pond loofs fine to me.

I'd maybe imagine to have less water, like just a small fall and some muddy water, low level of water, it should make sense in a marsh, but of course i'm not giving you a road to follow lol, i mean this is just an opinion/vision I share, as I do with other people's works in here. i mean, don't take it as a rule lol.

I think you are going great, but I decided to do not open this post anymore! I want to keep the surprise effect and check your work all in once. Will be hard, i'm such a curious persona

One hug!