The socialite attended a hearing in New York to show a judge that she is serious about her claims against the underwear business.
Paris and Le Bonitas are embroiled in a lawsuit over a product arrangement gone wrong.
The 31-year-old arranged a five-year deal to create a line of briefs, pajamas and swimwear with the company, however the project fizzled out for unknown reasons.
Paris is not only trying to claim money from the brand but they are seeking a financial settlement from her too.
The star showed up to federal court where lawyers argued key issues for each side.
A source told TMZ.com that she showed up because she wants the court to know how important the case is to her and her personal brand.
She is suing for more than $1.5 million - the amount she was supposed to earn in royalties.
Meanwhile Le Bonitas is suing for more than $200,000.