Children of Menelaus
Hermione — by Helen Nicostratus — by Helen or a slave Megapenthes — by a slave, Pieris or Tereis Xenodamus — by the nymph Cnossia Aethiolas — by Helen? Maraphius — by Helen? Pleisthenes — by Helen?
Homer's Odyssey 4.5 He was bringing Alector's daughter from Sparta for his son, mighty Megapenthes, grown up, who'd been borne him by a slave. The gods no longer made a child appear for Helen after she gave birth to her first child, lovely Hermione, who had the form of golden Aphrodite.
Apollodorus' Library 3.11.1 Now Menelaus had by Helen a daughter Hermione and, according to some, a son Nicostratus; and by a female slave Pieris, an Aitolian, or, according to Acusilaus, by Tereis, he had a son Megapenthes; and by a nymph Cnossia, according to Eumelus, he had a son Xenodamus.
Pausanias' Descriptions of Greece 2.18.6 When Orestes became king of the Lacedemonians, they themselves consented to accept him for they considered that the sons of the daughter of Tyndareus had a claim to the throne prior to that of Nicostratus and Megapenthes, who were sons of Menelaus by a slave woman.
Laurentian Scholiast on Sophocles' Electra v539 [Hesiod said] Helen bare to Menelaus, famous with the spear, Hermione and her youngest-born, Nicostratus, a scion of Ares.
Venetus A Scholia on Homer's Iliad [Ariaethus said] Helen and Menelaus had a child, Maraphius, from whom the race of the Maraphii descended in the Persians: as for the Nicostratus of Cinaethon, among the Lacedaemonians two children are honored, Nicostratus and Aethiolas.
Scholia on Euripides' Andromache v898 Lysimachus and some others report that Nicostratus was also born from Helen. But the one who gathered the Cypriot tales says that it was Pleisthenes who came to Cyprus with Aganus, the child born to Alexander from Helen.