What does " her feet barely touched the ground " mean?

What does the word precocious mean in this sentence

Cancer, ‘the big c,’ as it is often called. her doctor felt sure but ordered more tests to confirm his suspicion. while cervical cancer in a woman julianne’s age was rare, her doctor admitted, it certainly was not unheard of in her demographic group. her doctor explained that this type of cancer is often caused by a common virus that many women do not even realize they have. the human papilloma virus can lead to this type of cancer if a woman’s immune system does not fight off the virus in its initial stages. julianne was devastated. her doctor began to discuss treatment options and suggested an oncologist specializing in this type of cancer, but julianne heard very little of what he said. her head was spinning with questions. overwhelmed, she wondered how she would break the news to her family and friends. according to the article, a physician specializing in the diagnosis and treatment of cancer is called

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