The Scarlet Ibis

The surprise was Doodle walking across the room to the table on his birthday.

At breakfast on our chosen day, when Mama, Daddy, and Aunt Nicey were in the dining room, I brought Doodle to the door in the gocart just as usual and had them turn their backs, making them cross their hearts and hope to die if they peeked. I helped Doodle up, and when he was standing alone I let them look. There wasn't a sound as Doodle walked slowly across the room and sat down at his place at the table. Then Mama began to cry and ran over to him, hugging him and kissing him. Daddy hugged him too, so I went to Aunt Nicey, who was thanks praying in the doorway, and began to waltz her around.

What surprise do the brothers present to their parents?