LiAngelo Ball's still got 1 person 100% behind him after his embarrassing arrest in China -- and we're not talkin' about LaVar, Lonzo or LaMelo.
LiAngelo's high school sweetheart, Isabella "Izzy" Morris, just shared a pic of her and 'Gelo with the caption, "Old pic, same love" ... essentially confirming she's stickin' by her man through the hard times.
Her timing's pretty on point -- the middle Ball bro is literally in the air flying back from Shanghai ... after Donald Trump hit up Chinese President Xi Jinping to help bring LiAngelo and his 2 UCLA teammates back to the States.