How much longer until she gives birth?

I have a red wag platy who’s stomach is squared off and looks like she’s about to pop! How much longer until she gives birth?

Is the fish still eating?

Assuming she is pregnant, she will probably give birth in the next day or two.

Make sure there are lots of plants in the tank.

Feed the fish 3-5 times per day so they are less inclined to eating the babies. Monitor the water quality and do regular water changes to compensate for the extra food. Use a plastic container to scoop the babies up and put them in a separate tank or breeding net. Feed the babies on a powdered fry food or some crumbled up flake.

She is still eating but not as much as usual. She goes to the corner every now and then but a few minutes later she comes back out and swims with the other fish

If she is still eating then she is fine.

Hiding in plants or behind ornaments is something female livebearers do when they are in labour. They look for a calm sheltered area with lots of plants and give birth there.