The character credited as Engineer's Daughter in Transformers: Dark of the Moon is named Madeline Singer, a name established in the novel adaptation of the film. She is a young girl and the daughter of Bob Singer, an engineer working at NASA, and his wife Julia Singer. The family resides in a suburban home where much of her brief appearance in the story takes place.

In terms of personality, Madeline is portrayed as an innocent and trusting young child. She displays a childlike curiosity and friendliness, particularly towards robots, as she is delighted to find a small pink robot and brings it inside her home without fear. Her behavior reflects the openness and lack of suspicion typical of a young child, as she does not perceive the danger that the robot represents.

Madeline's primary motivation within the narrative is simple and age-appropriate: she is playing outside on a swing when she discovers the small Decepticon, Laserbeak, in its pink robotic form. Her actions are driven by a desire to interact with what she believes to be a friendly plaything, as she takes the robot inside to read it a book. This innocent act inadvertently facilitates Laserbeak's access to her home.

Her role in the story is small but significant as an entry point for a Decepticon attack. She unknowingly brings Laserbeak into her house, where her mother eventually discovers them. This discovery triggers a confrontation that leads to the death of her father, Bob Singer, at the hands of Laserbeak. The film presents her primarily as an unwitting participant in this tragic event, highlighting the collateral danger posed to ordinary humans by the secret war between Autobots and Decepticons.

Madeline's key relationships are with her parents. Her father, Bob Singer, is an engineer who had been helping the Decepticons cover up information about their activities on the Moon. Her mother, Julia Singer, is the one who finds Madeline with the pink robot and attempts to intervene. The film leaves the fate of Madeline and her mother ambiguous after the attack on Bob Singer. However, the novelization of the film strongly implies that Laserbeak kills both Julia and Madeline to eliminate all witnesses to the assassination. Regarding development and notable abilities, the character has no significant arc or changes throughout the film. She possesses no special skills or abilities, serving instead as a representation of human innocence caught in the larger, violent conflict.