The couple filed a petition to become the temporary guardians of a 16-year-old girl who is "dear friends" with one of their three daughters, according to court documents obtained by PEOPLE.
The Avatar director said the teenage girl lived with her biological parents in New York until September 2019. The girl's parents began to experience "health challenges and financial hardships approximately one and a half years ago rendering them increasingly unable to care" for her, the Camerons claim in their petition.
Cameron and his wife say the girl's parents have separated and are currently homeless while living apart in two different states with no "permanent residence" for the teenager to safely stay.
The couple's daughter and the teenager "maintained a close friendship, connecting online daily and even visiting each other in their respective hometowns," according to the couple.
The teenager has been living with the Cameron family at their California home "since September 2019." The teen has been enrolled at the private school founded by Amis Cameron, MUSE School, and has been given "a wholesome and stable home environment" where she has been cared for "as one of their own children," the couple said in their petition.
They say the teenager is now "thriving" under their care and that "she wishes to continue to be cared for" by the couple with the permission of her parents and grandparents.
The couple is asking the court to approve their petition for temporary guardianship to be able to "travel out of state and internationally with the minor." (Cameron has been busy directing the Avatar sequels in New Zealand.)
The director shares three children with Amis Cameron: daughters Claire, 19; Quinn, 16; and Elizabeth 13. He also has a 27-year-old daughter, Josephine, from his marriage to Terminator star Linda Hamilton. Amis Cameron has a son, Jasper, 30, from her previous marriage to actor Sam Robards.