My little brother has some really interesting adventure stories. Once, he went on a camping trip with his friends. They got lost in the woods but managed to find their way back by following a stream. It was a scary yet exciting experience for him.
For a little brother in a diaper, an adventure could be going on a walk with his family in the woods. He might see squirrels running up trees and birds flying overhead. And if he's really lucky, he could find a small stream and splash his hands in the water while his diaper keeps him dry (at least for a while). It's all new and exciting for a little one like him.
The little brother went on an adventure in the forest. He followed a colorful butterfly and got lost. But he was brave. He remembered the things his father taught him about survival. He found some berries to eat and a stream for water. Eventually, he followed the sound of a nearby highway and found his way back home.
Our first time exploring an old abandoned house in our neighborhood was quite an adventure. We were a bit scared but also very curious. We found some old trinkets and it felt like we were on a treasure hunt. It was a unique experience that brought us closer together as brothers.
They could go on a hike in the forest together. Discovering a hidden stream, they might have a great time skipping stones and looking for little fishes.
Our first time fishing together was memorable. We sat by the lake for hours, waiting for a bite. I remember my brother caught the first fish and he was so excited. We learned patience during that time and also how to handle the fishing equipment properly.
Once, a little sister had her first time on a roller coaster. She was terrified but also excited. As the coaster climbed up, her heart raced. When it plunged down, she screamed but also laughed. After that, she couldn't stop talking about how amazing it was.
I don't really know who Shelby Day is in this context as I haven't read the book. But I assume Shelby Day is the author of the novel who has created this story about the lost girl.
It might also be a term of endearment for a younger male friend or acquaintance. In some groups, people use 'brother' in a friendly way, and 'little brother' could be a specific person within that group who is no longer interested in stories.
There's not enough information to say exactly who the little brother is. He could be an ordinary boy in a family who is the youngest among his siblings.