Not much is known about Delly, but what is known is that she is very nice and was a friend to Peeta Mellark since the time that they were little children. She used to tell people that he was her brother. Delly was also in the same class as Katniss Everdeen and Peeta, and was said to admire Katniss.
The Hunger GamesEdit
When Katniss and Peeta were having a meal in the Capitol along with Haymitch, Cinna, Portia, and Effie Trinket, the Avox, Lavinia, waited on them. Katniss claimed to recognize Lavinia but after Effie and Haymitch explained that Avox's are traitors, Peeta chimed in claiming she just looked like someone they knew from District 12. That someone being Delly Cartwright. Lavinia and Delly look nothing alike in reality but Katniss was grateful for Peeta's discretion.
After Peeta was saved from the Capitol, Delly was one of the only People that could calm him down and would try to convince him of all the good things Katniss did. When Delly met Katniss, she was honored and happy to meet the mockingjay. Katniss informs her of Peeta and his condition. Delly visits Peeta and tries to get his memory back. Peeta is happy to see her and asks her what has been happening. Delly becomes sad and tears up when she tells him that District 12 was burned down and that his family is dead. Peeta is enraged and shouts that it is Katniss' fault and that she is a muttation. One time at lunch Peeta was allowed to eat with everyone and he was rude to Katniss and after Katniss and Gale left, Delly was very angry at Peeta and yelled at him for treating Katniss so badly.
Delly has a younger brother who also survived the bombing of District 12. However, her parents who owned a shoe shop in town, did not survive.
In The Hunger Games, Delly Cartwright is described as a pasty-faced, lumpy girl with yellowish hair. In Mockingjay she is said to look older with her long yellow hair in a practical braid instead of curls. She's also a bit thinner. Katniss said she remembers Delly being one of the few kids in District 12 with a few pounds to spare.