Age is relative, but Eris is a personified concept and the daughter of Nyx in most myths. There are some, however, that list Eris as a daughter of Ares. So the answer is "yes and no".
Ares
Eris is Ares's sister. She is the goddess of contention.
Eris is a daughter of Nyx alone, or of Nyx and her consort Erebus. Another Eris is the daughter of Zeus and Hera, sister to Ares.
Eris is the daughter of Zeus by Hera, her twin brother is Ares. She is also called Enyo.
Eleithyia, Eris, Hebe, Hephaestus, and Ares.
Eleithyia, Ares, Hephaestus, Hebe, Eris.
Olympus, alongside Ares her twin brother in Greek mythology.
yes,because eris god of chaous had a twin in mythollyg
Hades is older. Hades is one of Zeus's older brothers who were swallowed by their father, Cronus. Ares is Zeus's and Hera's son. Hera was also in Cronus's stomach, and after her release (along with Hades', Poseidon's, Hestia's, and Demeter's) they had Ares. So Hades is older.
Oenemaus, father-in-law of Pelops, was a son of Ares. Ares's father was Zeus, his mother was Hera. His godly children include Eris and Polyeoceus.
Eris, the sister and companion of Ares, the god of war.
With Zeus: Hebe, Ares, Enyo, Eileithyia, Hephaestus. Typhôn and the Charites/Graces are also said to be her children.