When Melody is eight years old, her mother becomes pregnant. With Melody having been born with cerebral palsy, her parents have great fears that her sibling will also have this disorder. Baby Penny, however, is later born able-bodied.
Melody experiences feelings of jealousy towards Penny, seeing her reach milestones that Melody herself will never be able to reach due to the disease that she was born with. Despite these feelings, Melody loves her sister and derives great joy from watching her grow.
The effect of Melody's cerebral palsy is that her body is rigid and uncooperative, meaning that she has to use a wheelchair. Despite her inability to speak, her mind works perfectly, which leads to immense frustration. Though she has become more self-sufficient over the years, Melody cannot help but see the contrast between her life and Penny's. Being the good person that she is, however, her love for her sister far outweighs any jealousy that she may feel from time to time.
Later, Melody tries hard to protect Penny and feels immensely frustrated when their mother cannot understand her non-verbal warnings that Penny has gone outside into the road unsupervised. Had Melody been able to verbalize her concerns, she could have prevented Penny from being hit by a car.