Darlene was Shorty's ex-wife.
She first appeared in "Treehouse", when both her and Shorty ate dinner with Jay and Gloria at their house. Her husband spendt a lot of time with her, while Gloria and Jay hardly ever did something together. Shorty invited Jay and Gloria to dance salsa and Darlene told Gloria that she would be doing her a favor because Shorty never stopped dancing.
Jay rejected the offer, which made Gloria so angry. But later, after Jay took a pill (which turned out to be orange flavored baby aspirin), Mitchell gave him to dance, he finally went to dance salsa with Shorty and Gloria.
She reappeared in "Three Dinners", and again was seen with Shorty at another dinner at Jay and Gloria's house. During dinner, Darlene told Gloria that telling jokes in a second language is hard, and told her something in Spanish. Darlene said that they were learning Spanish because she and Shorty were moving to Costa Rica.
Shorty returned in "Sex, Lies & Kickball", and said that Darlene left him for another man after he lost everything and began not spending much time with her.