What promise does Winnie make to the toad in Tuck Everlasting?

Winnie promises the toad that she will leave home.

Winnie is feeling a little isolated at home, and wants to stretch her wings.  She tells the toad that she is going to run away from home to have an adventure.

Winnie Foster sat on the bristly grass just inside the fence and said to the large toad who was squatting a few yards away across the road, "I will, though. You'll see. Maybe even first...

Winnie promises the toad that she will leave home.

Winnie is feeling a little isolated at home, and wants to stretch her wings.  She tells the toad that she is going to run away from home to have an adventure.

Winnie Foster sat on the bristly grass just inside the fence and said to the large toad who was squatting a few yards away across the road, "I will, though. You'll see. Maybe even first thing tomorrow, while everyone's still asleep." (Ch. 3)

Winnie has befriended the toad partly because there are not a lot of kids around for her to play with.  She lives in a house in the woods and feels isolated, telling the toad “I don't think I can stand it much longer.”  This leads her to want to see what the world has to offer.

Winnie feels stifled by her mother and grandmother’s attention.  She thinks they are always fussing over her and don’t give her any room to breathe.

"See?" said Winnie to the toad. "That's just what I mean. It's like that every minute. If I had a sister or a brother, there'd be someone else for them to watch. But, as it is, there's only me. I'm tired of being looked at all the time. I want to be by myself for a change." (Ch. 3)

Winnie gets her wish when she wanders into the woods and accidentally drinks from the immortal spring.  Because of this, Jesse and his parents have to take Winnie with them so that they can explain the situation to her.  The Tucks mean well, but being kidnapped is frightening to Winnie at first, until she learns that the Tucks are good people. 

The experience leads Winnie to become more grown up and gives her something to fight for when Mae Tuck gets arrested.  Getting away from home turns out to be an eye-opening experience for Winnie.  She sees the world as a bigger place.  However, she still chooses not to become immortal.