Hephaestus both was at one point a child and later had a children.
Hephaestus is the son of Zeus; or if the child of Hera alone, Zeus is his uncle.
Hephaestus
Hephaestus.
Hephaestus spend his younger years forging metal into lovely things for Eurynome and Thetis.
he was mad
Hephaestus and Athena "had" one child, Erichthonius, where Hephaestus tried to go for Athena and ended up getting her leg. She wiped off her leg and threw it to the ground, where Gaia the Earth Goddess was fertilized.
It depends on which telling of mythology you go by. There are some versions which make Hephaestus not Hera or Zeus's son at all, but of Talos.
Hephaestus was considered the ugliest of Zeus and Hera's children
Since his father was Zeus, he has many siblings. Any child of Zeus was a sibling to Hephaestus.
It was Ares (Mars in Rome) and Hephaestus (Vulcan in Rome). He preffered Athena over Ares and did not like Hephaestus's looks.
She was a virgin goddess who "adopted" the child of Hephaestus's seed made by Gaea, Erikhthonios.
Hephaestus originally had one biological son, who was Erichthonius. He was 'born' when Hephaestus tried to rape Athena. However she escaped him and his semen fell to the ground, and actually impregnated Gaia. Athena became to child's foster mother. There are some myths that Hephaestus did have extra 'sons' but they themselves could be foster children Hephaestus took care of during his exile. And they were Palaimonius and the 'Kabeiroi' on the island of Samothrace - Possible a group of craftsmen, who too were slightly crippled like Hephaestus.