Option 1: precocious -> describes a child who displays abilities or maturity beyond their age.
Option 2: pernicious -> means harmful or destructive, which is completely negative and doesn't fit.
Option 3: amiable -> means friendly and pleasant, but doesn't capture the maturity aspect.
Option 4: conscientious -> means diligent and careful, but doesn't specifically mean mature beyond one's years.
Hence, Option 1: precocious -> The context emphasizes that Nitika, at just seven years old, "understands her mother's pain and comforts her like a grown up," which perfectly describes precocious behavior - showing emotional maturity and understanding far beyond what's typical for her age -> correct