Melyssa Sayong had twice beaten cancer, but she died Monday after a painful relapse.
ABC7 initially interviewed the Sayong family in November 2014, when they were intermittently homeless and living in a motel after 2012's Hurricane Sandy devastated the Eastern Seaboard.
With help from the Santa Ana Police Department and local nonprofit organizations, the Sayongs were able to move into an apartment in October 2015.
"Our thoughts & prayers are with the Sayong Family during this difficult time," the police department said in a tweet on Tuesday. "Hearing the loss of Melyssa breaks our hearts #rip."
A GoFundMe page, titled "Help us put a little angel to rest," has been created to help pay for Melyssa's funeral expenses.
As of Thursday afternoon, the campaign had raised $805 of its $3,500 goal.