For those who have forgotten, here's Booklist's brief plot recap of Wrinkle: "Two children, accompanied by an older boy, go on a search for their missing scientist-father -- a dangerous search that takes them through space by means of a 'tesseract,' or wrinkle in time, to the dark planet Camazotz, whose puppetlike inhabitants are controlled by IT, a disembodied brain." Meg, of course, is one of those children. Spoiler: She defeats the brain.
In 50 years, a lot has changed in young adult writing -- parts of Wrinkle seem positively quaint, and there is a religious theme that runs throughout the book in contrast to the reality TV-informed "beyond religion" depiction of a futuristic dystopian society in The Hunger Games. But the traits of inspiring girl characters have remained much the same.
As one blogger points out at E-Femmera, "Like her spiritual descendant Katniss Everdeen, Meg Murry falls into the category of 'unlikely hero': she initially has no interest in fighting evil or making a stand, and is grudgingly dragged into adventure by Charles Wallace and the Mmes [Whatsit, Who and Which]." If Katniss had had her druthers, the Hunger Games wouldn't have even existed, and both she and Meg are driven into dramatic action because of their deep love for a younger sibling. Katniss volunteers as tribute so that her younger sister, Prim, does not have to fight, and surely die; Meg defeats the horrible omnipotent brain that makes everyone the same (read: Communism) with her love for her little brother, Charles Wallace, whom she alone can save. (Both girls' siblings are also impressively wise despite their youth.) Elsewhere in family relations, Katniss and Meg both love their absent fathers deeply, even embodying them in some ways, and are invested in "protecting" their mothers. Both also confront the fact that a parent is flawed throughout the course of the books.
In terms of romance, and, hey, there has to be a little, Katniss and Meg are adored by boys despite their supposed "plainness." On the Katniss side, we have her movie-ready love triangle with Gale and Peeta (Team Peeta!). Meg, on the other hand, is complimented on her "dreamboat eyes" by Calvin O'Keefe, an older and more popular boy who goes to her school, and who also travels with her "tesseracting" through the universe. Later in Madeleine L'Engle's Time Quintet series, Meg and Calvin marry. We won't tell you what happens with Katniss.
Still, unlike more passive girl characters (see Twilight's Bella Swan), romantic love is not the main story here -- it's only a sidebar. Further, the girls make choices for themselves, rather than having something chosen for them. Where they don't have a choice, as with the reality of the Hunger Games itself, or the the "dark forces" at work in Wrinkle, they choose to do things in their own way. There is something deeply, and uncomfortably, at stake for both of them. Like, life and death at stake.