The 15-year-old Springfield Lakes boy was charged on Thursday after being released from the Princess Alexandra Hospital, where he'd been taken on Monday.
Earlier on Thursday, a 13-year-old Inala boy initially only charged with three offences had four counts of attempted murder, three counts of grievous bodily harm and one count of deprivation of liberty added to the list of accusations against him.
Police were called to the Kefu family's Coorparoo home, in Brisbane's east, early on Monday morning after the group allegedly broke into the house.
Police allege it was a "burglary gone wrong" and not a deliberate targeting of the family.
Kefu, 47, his wife, 21-year-old son, and 18-year-old daughter are recovering well from the alleged attack. He and his son have both undergone surgery for their injuries.
"Wow. Humbling to see the outpouring of love and well-wishes from family, friends, community members and the general public," Kefu said on social media on Wednesday.
"We are all doing well. Josh, Madi & myself are out of hospital, and we're hoping Rach will be able to join us tomorrow.
"We just want to say thank you for everyone's support we feel very lucky and grateful."
All four boys, three aged 15 and one who is 13, have been charged with 11 offences each, including four counts of attempted murd and three of grievous bodily harm.
They were all denied police bail and due to appear before the Brisbane Children's Court.