Cleocharia is a Naiad nymph named by Pseudo-Apollodorus as wife of the earth-born Lelex and mother of Eurotas, eponym of the Laconian river and ancestor of Sparta through his daughter Sparta. Pausanias inserts Myles between Lelex and Eurotas and does not name Cleocharia.
Adapted from Wikipedia, "Cleocharia" · CC BY-SA 4.0
I.Wife of Lelex
Apollodorus (Bibliotheca 3.10.3) makes Eurotas the son of Lelex — autochthonous first king of Laconia in that account — by the Naiad Cleocharia. Eurotas gives his name to the river and begets Sparta, who marries Lacedaemon.
Cleocharia thus stands at the root of the Apollodoran Spartan river-and-city eponyms as a water-nymph mother.
II.Pausanias' silence
Pausanias' Laconian antiquities give Lelex a son Myles and make Eurotas son of Myles, without mentioning Cleocharia. The Naiad belongs to the Apollodoran handbook stemma rather than to the Periegete's local sequence.
Both versions agree that Eurotas is an early Laconian eponym; they disagree on the intervening generation and on the mother's name.
III.Scope
Cleocharia has no independent myth beyond this motherhood. She should not be confused with other Cle- names in Spartan or Argive lists, nor treated as a panhellenic cult figure.