Cleopatra of Mauretania, Cleopatra IX, or a younger Cleopatra Selene (Cleopatra in Greek: η Κλεοπàτρα) could have been a possible daughter of Greek Ptolemaic Princess and later Queen Cleopatra Selene (II) and African King Juba II of Mauretania.

The possible evidence of her existence is:

• In Athens Greece, there are 3 inscriptions dedicated to the children of King Juba II. These descriptions name Juba, however there is one inscribed ‘daughter of King Juba’, whose name is not given. Ptolemy (Juba's son) dedicated an inscription for himself.
  
• An Athenian epitaph, is dedicated to the memory of a daughter of a Libyan King. The name of the attendant is lost. Libyan in Ancient Greek, is a loose description of any part or anybody from North Africa. The Ancient Greek traveller Pausanias, states that King Juba II was known in Athens as ‘Juba the Libyan‘.
  
• Cleopatra Selene (II), was patriotic of her Ptolemaic and Greek ancestry. She named her only son Ptolemy and the surviving archaeological evidence, which represents she inherited the will and perseverance of the Ptolemaic women.
  
  

Source

http://www.geocities.com/christopherjbennett/ptolemies/selene_ii.htm