You'll notice that the Aquaman she draws is the 1990's version, from the Peter David-written volume of Aquaman, with the beard and the harpoon hand. Why that Aquaman? Here's what Beaton wrote under the strip:
As new as I am to learning about superheroes, everything that is well known to everyone else—like the fact that Aquaman is regarded as kind of lame—is new and hilarious. I read a bit about Aquaman growing a beard and having a harpoon hand and living in a cave and talking to spirits or something, and thought, how can anyone not like this guy? This crazy dude living under the water. Anyway that is the only version of Aquaman that I am really into.
I could definitely get into a "crazy dude living under the water" take on Aquaman, especially as drawn by Beaton. She certainly has a way with DC superheroes. If you missed it, here's her Wonder Woman strip from last fall.