Lillian Marie Jill "Lil" DeVille is the twin sister of Phil DeVille and the tertartagonist of the Nickelodeon shows Rugrats and All Grown Up!, and are among the series' original main characters. They are fraternal twins, because Phil is male and Lil is female, but both have identical traits. The real difference is that Lil wears a pink bow on her hair, Phil wears overalls while Lil wears a jumper, Phil wears training shorts while Lil wears a diaper, Phil's shoes are blue while Lil's are pink, and (for the most part) Phil doesn't have any ear lobes like Lil (though sometimes, he is shown with them, too.) She is possibly the love interest of Chuckie Finster.
Of course, they are even more different in All Grown Up! because they no longer dress similarly.