Since the 2009 death of Michael Jackson, the pop superstar’s three children — Prince, 20, Paris, 19, and Blanket, 15 – have done their best to lead normal lives.

“The kids live like Michael is constantly looking down upon them,” a family friend tells PEOPLE.

The insider says that Blanket “has had the most problems adjusting after Michael died. He acted very lost and extremely upset.”

After being bullied for years, in 2015 he changed his name to Bigi.

And while Bigi is “shy around people he doesn’t know,” he is now “confident” at his Los Angeles private school and is focused on grades, sports, movies and hanging out with his friends and nearly 30 cousins.

Sources do no know who is directly in charge of the teenager — whose mother was an unidentified surrogate — due to ongoing family disputes, but Bigi lives at grandmother Katherine Jackson’s Calabasas, California, mansion under the custody of Katherine, 87, and co-guardian T.J. Jackson, 38, Michael’s nephew.