After an 18-month battle, Watkins passed away on November 14 at the Lurie Children's Hospital of Chicago.
"We were praying for a different outcome," Anthony Edwards, who was Watkins' legal guardian, told the Chicago Tribune. "But Ben's lungs could no longer give him the air he needed to breathe. It's been devastating."
The Tribune reports that Watkins' father Michael Watkins shot and killed Ben's mother, Leila Edwards, 43, before taking his own life. Investigators ruled it a murder-suicide.
"After losing both of his parents … we have marvelled at Ben's strength, courage and love for life," his guardians said in a statement. "He never, ever complained.
"Ben was and will always be the strongest person we know.
"When Ben's rare illness was shared with the world, he was so heartened by the outpouring of love he received from every corner of the globe – especially here in his hometown of Gary, Indiana.
"Ben suffered more than his share in his fourteen years on this Earth, but we take solace in that his suffering is finally over and in that, in the end, Ben knew he was loved by so many."
Celebrity chef Gordon Ramsay paid tribute to Watkins on Twitter.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Helpline: 1737
If it is an emergency and you feel like you or someone else is at risk, call 111.