αὐτὰρ ἐμοὶ γένος οὐράνιον· τόδε δ’ ἴστε καὶ αὐτοί.
δίψῃ δ’ εἰμὶ αὔη καὶ ἀπόλλυμαι· ἀλλὰ δότ’ αἶψα
ψυχρὸν ὓδωρ προρέον τῆς Μνημοσύνης ἀπὸ λίμνης.”
The Titans Chronos and Rhea were the parents of the Elder Olympians — of which Hestia is BOTH “eldest” and “youngest” because of a prophecy Chronos received before the birth of his children that he would have a son who would overthrow him as he had his father. Chronos would swallow his children at birth. The first one born was Hestia — followed by Haides, Demeter, Poseidon, and Hera before Rhea tricked Chronos by having him swallow a stone in the place of Zeus.
Although She herself did not have any children, her siblings did and Her nieces and nephews include Athena, Artemis, Apollo, Dionysus, Hermes, Hephaestus, Ares, and Persephone.
These are the CLOSE relatives of Hestia — although there are more that I haven’t been able to mention in a short post.