There was only one condition, there could not be any alcohol at the event.
When Mireyari found out that Phoenix House, a treatment facility for young people dealing with substance abuse, chose her as the candidate she was so excited.
"My first reaction, I was still shocked like I didn't know what to say like I was just sitting there trying to process what they had told me," said Pacheco.
Especially when an average quince can cost between $5,000 and $20,000.
Even though, Phoenix House focuses on treating those suffering with substance abuse this initiative all came from their Prevention Department.
"Our goal for the county is to prevent underage drinking...to reduce underage drinking. And little by little start changing the social norms in this community because the data shows us that underage drinking happens at these types of events," said Maribel Briseño, Prevention Coordinator.
Pacheco does not have any history of drug or alcohol abuse, and was chosen because she is a good student and very active in extracurricular activities outside of school.
This is the first free quinceañera that Phoenix House has offered and they are planning more for the future.
Mireyari's mother was very excited to have this beautiful day provided for her eldest daughter especially because of her background.
"For me it was a great idea because personally in my family's history, alcohol has been one of the problems that we've had so I thought it seemed like a great idea," Mireya Garcia.
The festivities had everything you could imagine; a party bus, hair and makeup for the ladies, a venue with Cinderella inspired center pieces, and Mireyari in a grand Cinderella inspired dress.