Melanie seems to be really aggressive, as humans were. She was hardened by the invasion; and grew up and matured quickly due to the fact that she had to raise and protect her brother. She is very strong, never gives up, and throughout the story, she comes to love Wanderer as a sister, and vice versa. She's willing to go to extreme lengths in order to save and protect the people she loves.
Melanie loves her brother, Jamie so much and he describes her as being thoughtful and benign. She also loves Jared, Melanie's lover.