If the pair is young/inexperienced they may not have any luck this first time around. If that is the case, then they will probably get it right the next time. Now that you have the nest bowl and nesting material, they should be all set for the next round.
some of my birds only lay one egg sometimes. i dont add nestbowls after they are laid. they just abandon the eggs. when she lays again just let her be where she wants to be that is always best. sometimes my birds lay only one, then a week and a half lter lay 2 more i would just leave the first egg a few days and if she doesent lay again and doesent go back to it toss it. she will lay again very quickly but your bowls in your boxes and let them use or not use them as they wish. i have at least 2 pair that lay out of the bowl all the time.