Marly doesn't see just one miracle; she sees many while she is at Maple Hill.

As they're traveling to Maple Hill, Marly listens to a conversation between her parents. Virginia Sorensen writes,

"When I was a little girl up at Grandma's," Mother said, "I was certain that Maple Hill was the place where all the miracles
had happened." Daddy didn't laugh. For a minute it was as if the two of them were holding their breath together. Then Daddy
said, "I'm afraid miracles don't happen any more—even at Maple Hill.

Her mother later tells her that her grandmother said the syrup coming up from the trees was the first miracle. For the rest of the story, Marly witnesses similar miracles—each of them comes from the natural world and helps her feel more at peace with herself.

Marly is told again that the sap running is the first miracle. She's told it happens in the spring when all the trees come alive again after the winter. She agrees that it's a miracle that she also sees at home in the park. Mr. Chris promises her that she'll see at least one miracle at Maple Hill every weekend she visits until school is out.

Marly's first miracle, though, is the sound of her dad singing. She's very happy to hear it.

Her next miracle is seeing a deer that turns and flees.

The next miracle is ice crystals shining on a tree outside her window.

She later thinks that she wakes up every day to a scarlet and gold miracle when she looks at the trees.

The next miracle is her putting food out and birds coming to enjoy it.

When the trees start producing sap, she finds it miraculous and loves to participate in the process.

Marly also finds it miraculous when the heavy bucket she's carrying suddenly feels light when she learns Mr. Chris is improving.