Ramos was supposed to graduate from California State University, Fullerton with a degree in criminal justice. But her seat was vacant. Her family was at the ceremony and received her diploma from CSUF President Mildred Garcia on her behalf.
The school posted on its Instagram account a photo of a reserved seat in Ramos' honor and also of her family holding a portrait of Ramos as they sat in the crowd.
"It means so much that you have joined us for this ceremony and we are honored by your presence," said Garcia. "Maribel was a vocal part of the CSFU family."
Family and friends couldn't have been more proud.
"It was a very special day," said Arturo Romero, Maribel's cousin. "My cousin Maribel deserved to be here. Unfortunately, this was taken away from her."
Ramos went missing on May 2. The 36-year-old's body was discovered in Modjeska Canyon May 16.
Ramos' roommate, 54-year-old Kwang Chol "KC" Joy, 54, is charged with killing her.
Prosecutors allege Joy got into a fight with Ramos after she told him to move out because he wasn't paying the rent. Authorities suspect there could also be another motive.
"He may have been infatuated with her and I don't know if that was necessarily mutual," said prosecutor Scott Simmons on Tuesday, when Joy made his first court appearance.
The Ramos family vowed to attend Sunday's graduation nonetheless. They wore Maribel's favorite colors white and pink to the graduation.
"It's been very emotional," said Susana Molina, Maribel's cousin. "We're here for her, supporting her. We're very proud of you Maribel. Everybody is here as a family to be here for her."
Ramos was described as a hard working student who was fully focused on graduating at the age of 36. The army veteran also served in South Korea and Iraq.
Joy's arraignment is set for June 7. He is being held on $1 million bail.
Ramos' funeral is set for June 2.
To raise money for the ceremony, Ramos' family are holding several fundraisers including a silent auction Sunday. The event will take place at Cantina Lounge located on the 2700 block of East Nutwood Avenue in Fullerton around 8 p.m.
For more information on how you can help, visit www.findmaribel.com/donations.html.