The woman alleged to have shot up Rihanna's luxury Los Angeles home pleaded not guilty to attempted murder when she appeared in court on Wednesday, as details emerged of a near miss for the global megastar.

The "Umbrella" singer and her partner, rapper A$AP Rocky, were in an Airstream trailer on the sprawling property when 35-year-old Ivanna Lisette Ortiz is alleged to have opened fire.

Rihanna told police she heard the sound of several rounds hitting the trailer, and opened the curtains to find bullet holes in the windshield directly in front of where she was standing.

She said she got A$AP Rocky, whose real name is Rakim Mayers, out of bed and told him they were being shot at as they both ducked to the ground, before rushing inside the property to make sure their three children and staff were safe.

Police said about 20 rounds had been fired. In addition to the trailer, they hit a patio area and a nursery room wall.

Bullet holes were also found at a neighboring property, a Los Angeles Police Department crime summary said.

Deputy District Attorney Alexander Bott told Los Angeles County Superior Court the gunfire from an assault-style rifle had erupted at a time several people were at home "putting numerous lives at risk" in the March 8 incident.

He said Ortiz, who was arrested in a vehicle with a rifle, ammunition and a disguise -- a wig -- had behaved in a manner that was "extremely dangerous."

Ortiz, who is from Florida, entered not guilty pleas to one count of attempted murder involving Rihanna, whose real name is Robyn Fenty, along with 10 counts of assault with a semiautomatic firearm.

She also denied two counts of shooting at an inhabited dwelling and one count of shooting at an inhabited vehicle, as well as allegations that she personally and intentionally discharged a rifle.

The defendant was ordered to return to court April 8, and is being held in pre-trial detention after failing to pay a $1.875 million bail.

Los Angeles County Superior Court Judge Theresa McGonigle also ordered that she not practice as a speech-language pathologist in California, where she has been licensed since 2016, while the criminal case is pending.

Ortiz could face life imprisonment without parole if convicted.

Entertainment news outlet TMZ reported Ortiz has previously been involuntarily committed.

A Facebook page that appears to belong to her includes a number of videos and posts that refer to celebrities including Rihanna, Kim Kardashian and Cardi B.

One post tags Rihanna, whom she challenged "to say something to me directly instead of sneaking around like you talking to me where I'm not at."

In another video, she claims Rihanna wants to kill her.