Why not give names to children? It doesn't seem like it would affect survival in any way.
The ending seem way too happy and dream like unrealistic so did they actually drown in the river and this is just flashback when dying which would explain my other two questions.
Why can be they out in yard in daylight safe from monsters, what's so special about it, it was not completely covered with plants.
What are their supplies for so many people living there, how can they grow so much food? It seem unrealistic.
Also why not have children roped to her in river and when walking in forest to avoid getting lost from each other?