Doja Cat had teeth knocked out by her brother, according to a petition for a restraining order submitted by her mother.
Deborah Sawyer, 62, requested a court to include Doja Cat in a temporary restraining order against her son, Raman Dalithando Dlamini, Sky News's US partner network NBC News reported.
Ms Sawyer claimed Doja Cat - whose real name is Amala Ratna Zandile Dlamini - had "experienced physical harm such as teeth being knocked out and bruises and lacerations".
A judge partially granted the order, pending a 31 January hearing, but said there was "insufficient good cause shown" to include Doja Cat and that the singer could file for her own order.
"Raman has destroyed and stolen property," claimed the petition, which was filed in a Los Angeles Superior Court.
"Raman has verbally assaulted her in a very degrading and demeaning [manner]. Raman has made her feel unsafe and traumatised."
Raman Dlamini, 30, had allegedly abused his mother "three to 10 times recently" and "several times in the past", according to the petition.
Ms Sawyer was also granted a restraining order against him in 2017, according to court records, and she says the most recent incident was on 10 January.
Then, she claims, he blocked her from her home and choked and hit her - with some of the abuse witnessed by her grandson.
The parents of the teenager were not identified.
Ms Sawyer said she had "constant anxiety and fear" for her safety and wellbeing.
"I need these orders to protect the physical and emotional wellbeing of all parties listed," the petition stated.
"I am not only worried and fearful of physically violent episodes, but the tremendous mental and emotional damage that is being done."
Representatives for Doja Cat did not immediately respond to a request for comment.
A publicly listed phone number for Raman Dlamini was not available.