I actually kind of love it and think it's a good example of the show continuing to do interesting things with the characters that aren't just predictable.
I mean, if you just go by how they come across on a surface level, who would you EXPECT the team slut to be? You'd pick either Zee or Kara, right? The fat-assed vamp or the curvy but muscular tomboy. They're the two most obvious candidates to be the slut of the group.
But it's not either of them. Instead it's the dweeby redheaded genki girl. Babs comes across as the nerd, the weirdo, not the slut. The idea that she's the most interested in boys of the group is something unexpected, which makes it interesting. She very pointedly does not go out of her way to look sexy, yet she seems to have a bigger sex drive than any of the girls that do.