Bart Baker parodied Avril's infamous "Hello, Kitty" music video, making fun of its dubstep and rap nature.
Not counting her songs being included in the "Do They Know?" challenges, Avril has been covered by the React channel twice. First was her infamous "Hello Kitty" music video in a 2014 Kids episode, then her entire career in a 2019 Teens episode which even features half of the kids who reacted to her previously.
Inside Job (2021) features Avril clones among other clones of celebrities and historical figures, as a nod to the urban legend which says that she died in 2003 and was replaced by a look-alike.
6teen has an episode where, to get the Clones to leave her, Nikki points across the store and says "Look, isn't that Avril Lavigne?" Especially delicious since the show is set in Canada, so it's possible in-universe that she might shop there.