Correct, fat bellies = female danios.
Fun fact... did you know that danios mate for life?
If you want to improve egg and fry survival you can put in some guppy grass a.k.a. naja grass, Java moss or Christmas moss, water sprite and / or cabomba. Those will give the eggs a place to fall where they won't be easily found and eaten. Fry will have a place to hide and forage for microorganisms growing on the plants.