When Cleopatra took her own life, she left behind her four surviving children.
Her firstborn, and only living child with Caesar, Caesarion, did not live for long after her death. She had sent him away from Egypt for his own safety, but he was falsely lured back with promises of being allowed to rule in her place. He was murdered by Octavian’s men, after he’d received advice that “Too many Caesars is not good". As Caesar’s biological son, he was too much of a threat to Octavian’s rule. It’s thought he was likely killed by strangulation, but no one knows that for certain, or what happened to his body. He was only 17 years old.
It was a different story for her children with Mark Antony. There were the twins Cleopatra Selene II and Alexander Helios, who were both 9 at the time, and Ptolemy Philadelphus, who was just 6. The three of them were taken to Rome by Octavian, and forced to walk behind his chariot in his Triumph Parade, chained to it with chains so heavy they could barely walk. This aroused not the scorn he’d been expecting, but sympathy for the poor young children. Octavian gave them to his sister Octavia, who had been married to their father, to be raised along with her children.
Neither of the boys would see adulthood, both apparently dying sometime before 25 B.C. There were rumours that Octavian had both of them killed, not wanting any adult sons of Antony and Cleopatra to remain alive.
Cleopatra Selene however, had a somewhat kinder fate. She was married to Juba II, King of Numidia and later Mauretania. She is said to have inherited the strength and pride in her heritage of the Ptolemaic women that came before her, and used the same titles as her mother on coins. She had at least one child, a son she named Ptolemy, and possibly a daughter named Drusilla. Her exact date of death is unknown, but she was placed in the Royal Mausoleum of Mauretania when she died. It is still visible today, and a fragmentary inscription was dedicated to Juba and Cleopatra, as the King and Queen of Mauretania.