Please, there is no need to stress a birthing female by moving her to a small and exposed environment.. it is best to leave her in the main tank or move her off to a separate tank a week earlier. She can actually die from the stress or birthing complications as a direct result of being in a "breeding net" or being moved.
http

/www.fishforums.net/index.php?/topic/253113-how-to-know-if-your-livebearers-ready-to-drop-fry-updated-150410/ Being told by you not to put her in the net/trap is pretty contradictory to what I learned in the forum, which is where I took advice on how to save the babies. You might message this person and tell him he is giving bad advice to newbies....oh and the momma is fine. I checked on her periodically throughout the night because I have also read that it is not uncommon for livebearers to die after giving birth anyway.
Hun, that is a thread about how to tell when a female is about to drop, not about best conditions for females to drop in

Nothing contradictory there. I would really love to see if you did have someone telling you that a small, bare, floating container is the best place for a pregnant fish to be, because that really would be absurd and require some correcting. The advice given by the OP seems sound, especially about not netting out pregnant females. The OP is also providing a better than average environment by adding plants to the box, to make the female feel more secure. If you want an example of what I consider to be a "good" environment for females who are about to birth and which is also on this forum and not by me, look at http

/www.fishforums.net/index.php?/topic/285369-molly-full-cycle/
The only reason it is not uncommon for livebearers to die during birthing is because it is not uncommon for them to be put into a really bad environment during birthing. From my own experience breeding livebearers in a relaxing environment for the female, only about 1 in 10000 birthings is not smooth. In practice, more like 1/5-10 female livebearers die during birthing. Yes, out of 1000s of birthings I have observed in my own fish, only one 5 year old female died during the actual birthing and she was dropping fry in lots of 150-200 by that age.. which is quite understandable why she died.
Basically, I have told you how to improve the life of your fish, and given you the reasoning for what I said. I recommend you think about it and do some more research. I can not and will not influence every person in the world who I think is doing something wrong, but I will give advice to a few, like you, on what I think is better.
Another thing I did forget to mention earlier is that the fry will not grow that well in one of those things because of the lack of swimming space, water circulation and they tend to get quite dirty.