Lucy Wilde is an agent of the Anti-Villain League (AVL).
Although initially introduced as a serious and stoic woman, she is generally very happy, enthusiastic, cheerful, and perky, shown when she happily exclaims after telling Gru she is his new partner. She is also quite alert at times, very athletic and skilled in combat.
In Despicable Me 2, she was initially assigned to find Gru and bring him to the headquarters of AVL, and later on becomes Gru's partner in the hunting of the thief of the PX-41 serum. During the missions, they start to realize their feelings and eventually become married.