I had loads of eggs, she's a few years old and does a pretty good job of hiding them but I've never collected any before. She lays most of them on leaves, which I've read is quite unusual for peppereds as they lay on the tank walls.
I have mine in a shallow plastic tub, one of those you get salad in from a takeaway about 3" deep. It seems ok! I have about 2" of water in it and the airstone is plenty to move the water surface but doesn't create much movement lower down. The fry aren't getting moved around by it at all! In fact I was watching one of them swimming at the surface earlier on a lot like the adults do, vertical just touching the surface. It had no trouble. Because the tub is floating in the tank it's really easy to do water changes, I just take the old water from the box with a turkey baster and squirt it into the main tank, then vice-versa to fill it up again. The airstone is one of the little blue ones about 3" long. I've attached it to the side of the tub with a sucker so it's fixed in place.
It just so happens that the tube is the perfect size to sit on top of my breeder box which I've stuck to the side of the tank, so there's no risk of it floating away across the tank. That's just luck though.