Where is the Cleopatra and Julius Caesar childrens or relatives?

Cleopatra and Julius Caesar were supposed to have had a son, at least according to Cleopatra. His name was Ptolemy XV or Caesarion. He was killed after Octavian conquered Egypt.
Cleopatra and Julius Caesar were supposed to have had a son, at least according to Cleopatra. His name was Ptolemy XV or Caesarion. He was killed after Octavian conquered Egypt.