McG's 2017 horror comedy, The Babysitter, and its 2020 sequel, The Babysitter: Killer Queen, are meant to be connected with a gap of only two years between movies, which brings Cole's age into question and possibly creates a massive plot hole.
Cole (Judah Lewis) and Bee (Samara Weaving) are the driving force of The Babysitter; Cole is the 12 year old kid that she's babysitting, and also her chosen "innocent" sacrifice when she and her friends are revealed to be part of a demonic cult. After Cole manages to escape her and her friends—most of them end up dying in the first movie—he's forced to grow up very fast in dealing with the aftermath. The aftermath of these events, which follow Cole two years later when he's a high school student who everyone thinks is crazy, is addressed in The Babysitter: Killer Queen. Just like in the first movie, Cole finds himself fighting the same members of Bee's cult, this time led by his trusted friend and classmate, Melanie (Emily Alyn Lind)—and he's still their chosen sacrifice.
Cole being an innocent 12 year old is a focal point of The Babysitter, and while he could still be in high school at the age of 14—likely a freshman—the events of the movie make him seem to be at least a year, if not two, older. There are other elements of The Babysitter: Killer Queen that don't quite gel with the first movie, such as Bee's age and greater purpose, which was brought into question by Samara Weaving's triumphant return toward the end of the movie. Bee's age can be explained through numerous, magical situations or influenced by her deal with the devil somehow, but as Cole is just a normal human, there's no reason why he wouldn't age normally.
In The Babysitter: Killer Queen, Cole is supposedly a junior in high school. This explains why his classmate, Melanie, is able to legally drive. In the United States, a driver's license can be obtained at 16, with a driver's permit is often acquired at the age of 15. While Cole is in the passenger seat during the scene where Melanie drives—a clear homage to one of the early scenes of The Babysitter where he's in the car with Bee—it's likely he's close to the same age, either 15 or 16. Also, in United States high schools, most juniors are aged at least 16, even 17 years old. Since he was 12 in the first movie, this is a minimum of 3 to even 5 years, depending on whether he's 15, 16, or 17.
Cole's relationship with Phoebe (Jenna Ortega) is also suspect, given his age. As the sequel takes place two years after the events of The Babysitter, he would be 14 years old, which is too young by most people's standards to be romantically and sexually active. A key moment in The Babysitter: Killer Queen is the reveal that Cole has lost his virginity to Phoebe, making him no longer an innocent—the ritual performed by the cult requires mixing the blood of the innocent, Cole's blood, with the blood of the sacrificed, then drinking it. The fact that Cole is no longer innocent means Melanie and the rest of the returning cult members from The Babysitter are immediately destroyed, presumably going back to hell for eternity.
Suspending disbelief, even if Cole was almost 13 during The Babysitter, he'd be almost 15 in The Babysitter: Killer Queen, which still seems too young for his overall growth, characterization, and doesn't coincide with him being a junior in high school, even at the start of the year. While McG is hopeful for the chance to make The Babysitter 3, which could answer a lot of the franchise's remaining questions, negative reviews for the sequel could come into play and prevent this plot hole—or the audience's questions—from ever being addressed.