Megan is a cruel girl who never gets tired of pranking her brothers. However, she is shown to be a good student, good friend and also helps other people sometimes.
She also acts innocently for her mother and stepfather, and thus they think she is completely sweet and don't believe her brothers when they tell them what she does. She acts like a five year old cause she doesn't know how to act her age! Mostly she can get away anything and mostly she usually gets her brothers in trouble with her parents.
Megan is primarily mischievous and sarcastic most times, but she also helps other people when they are in need, like helping Drake and Josh get out of the jail in "The Gary Grill". Still, she loves to prank and "torture" the lives of her brothers and think of it as a job. Megan also seems to not care if her brothers are happy or not when she pranks them. She is the youngest and mostly she can get away with anything and mostly she is usually gets away with anything and gets her brothers in trouble a lot of times.
Megan is also really good with machines and electronical stuff, as she has a secret spying panel in her bedroom and a briefcase full of spy devices. It is never explained where or how she obtains her gadgets.
She is also similar to Sam Puckett from iCarly and Jade West from Victorious.
Megan was born as Margaret Jessica Parker on ,May 14, 1994 as the younger sister of Drake Jared Parker (b. 1989), to an unknown father and Audrey Nancy Parker. At the beginning of the series, she and her brother are informed that Walter Nichols is to be their stepfather, and Josh Nichols is to be their stepbrother.
For most of the series, Megan is often the source of misery for her brothers, either because she wants to or because they provoke her. Occasionally, she does help out when they are in need.
In one episode, Megan has a boyfriend. Due to her brothers being overly-protected and sharing a dislike for her date, they try to break it off. At first, Megan is angry at them, but when she discovers that he is in fact, dating another girl as well, she breaks off the relationship, and forgives the brothers, but continues to bully them thereafter.
Relationship with other Characters
Drake Parker and Josh Nichols
Drake and Josh are Megan's older brothers and main (and actually, only) victims of pranking. She often calls her brothers "boobs" and likes to watch them fight or get punished. Yet, she admits she loves them in "Megan's First Kiss", where Drake and Josh act protective over her. The brothers also enjoy seeing Megan getting scared in "Alien Invasion".
Megan has a fine relation with her mother. However, she hides her pranks towards Drake and Josh from her and Walter, so Audrey isn't aware of that and always believes in what she says.
Megan seems to dislike Walter for thinking he is goofy. On the other hand, he thinks Megan is cute and sweet, mentioning it in many episodes. Megan also calls him by his first name, like in "The Demonator" and episodes after that.