Katara is a female waterbending master that is raised by her grandmother, Kanna along with her brother, Sokka.
When Katara was a young girl, her mother was killed in a Fire Nation raid. This event had a tremendous impact on Katara's life and personality and arguably shaped her into the person she became. She was very emotionally driven, involving herself completely in the heartache and needs of those around her. Placing her whole heart in the affairs of others, as well as bearing her own heartache, she was often easily reduced to tears. According to Sokka, Katara largely prevented their family from falling apart and took on many responsibilities to the point where she filled the void left by their mother (so much that he pictured her in place of his mother). As such, Katara had a very maternal personality and often acted as a motherly figure to the group, something that often irritated the rebellious Toph. Her loss was also part of what drove her in her fight against the Fire Nation, although she did not exhibit as much outward prejudice as her brother. She was also a bit of a stickler for morality, even to the point of causing Sokka and Aang to faint from shock when she stated she wanted to pull a scam, as she had berated Toph for scamming people.