The 17-year-old avoided looking at her father while she gave evidence, pulling her jacket up against her face to shield him from view.
She said he would sometimes make Nia's lip bleed and would swear at the 3-year-old, once telling her to "shut the f*** up or he would stomp on her face".
The worst incident Hoana witnessed involved Curtis strangling Nia with a scarf.
She said he wrapped the scarf around Nia's neck two or three times, then lifted her off the ground and held her in the air for 10 seconds.
"Her face turned purple and then he chucked her to the ground."
Upset by the incident, Hoana told Curtis she would stab him if he did it again. "He said I was a little bitch and he'd do it to me as well."
Under cross-examination, she admitted she had issues with her father and had lied to police about a conversation relating to Nia's murder. She also admitted being expelled from high school for smoking cannabis and cigarettes - all of which the defence said undermined her credibility.
Nia died on August 3 last year after being kicked in the head by Wiremu and Michael Curtis. Her mother Lisa Kuka was found guilty of her manslaughter, and two others were convicted of cruelty and assaults.