Despite what Jelani Maraj's lawyer has been suggesting, Maraj's sister Nicki Minaj will not testify on his behalf as he faces charges of predatory sex assault against a child.

Today, sources told TMZ of Nicki's decision to stay away from the witness stand. Yesterday, the ten-year-old brother of the alleged victim -- who is Maraj's stepdaughter -- testified.

The boy told the court that he walked in on Maraj raping his sister, who was 11 at the time.

The boy then testified that Maraj found him and slapped him in the face "about 10 times" while demanding he stay silent about what he saw.

Maraj’s lawyer David Schwartz alleges that the girl’s mother Jacqueline Robinson married Maraj in 2015 for the purpose of getting money from his famous sister. To do so, Schwartz claims Robinson got her daughter to lie to police about a sexual assault.

Schwartz argues that Robinson planted the semen of Maraj's that was found her daughter’s pajamas. He also told the court that Robinson tried to shake down Minaj, telling her ‘I can make the charges go away for $25 million."

Schwartz was hoping Minaj would corroborate that charge. Now it looks like she won't.

[Related: Details of Nicki Minaj's brother's child rape case emerge.]