Even if the mom is not cannabalistic, the fry will enjoy the ferns and the grass. You'll see most of them hiding in it (and probably in the corners at the top of the tank) especially for the first few days. Without predators, they'll comfortably swim the tank within a week. With predators, they'll mostly hang in it except during feeding time.
I'd probably also float something - I let a fake plant float at the top. Mine preferred hanging at the top than the bottom, although they did both.
Good plan on the waiting just a day or so. Enjoy it... it's exciting!