Sick platy adolescent

[KFav93]

I had this female platy since she was born. The passed couple of days she's had her fins clenched and she's hanging in the top corner. She looks a little bloated. When I fed the tank she has no interest in food. But she would swim around at the bottom, trying to avoid other fish. Eventually she makes her way back to the corner. There's only female platys in the tank. I haven't added any fish or changed anything lately. The only thing new is I just put flourish root tabs in last week for the first time. Only 2 in the gravel by my plants. Well I did a 35% water change 2 days ago and she's still not looking good. Could it be dropsy?

It's a 20 gallon tank.
PH 7.6
Ammonia 0
Nitrite 0
Nitrate 10
(Nitrate in source water is a 10)
I use prime water conditioner.

 

[KFav93]

 

[coralbandit]

I don't see the scales 'pine coned' like normal bloat?
Could the fish just be constipated?

 

[Angellove78]

You sure they are all females? Could be pregnant.

 

[flitabout]

really looks like she's pregnant