The family of 24-year-old Sydney Marquez, a recent Texas A&M neuroscience graduate from El Paso, is making an emotional appeal to the public to help keep her case in the spotlight amid an ongoing search in Houston. Sydney vanished on December 11, 2025, while visiting friends, leaving her loved ones in agonizing uncertainty.

Sydney’s parents, Raul and Luz Marquez, recently appeared on NewsNation’s “Banfield” to share their heartbreak and urge anyone with information to come forward. “She just was a bright, happy person and loves her family,” Luz Marquez said, describing her daughter as someone with big plans for the future who left behind personal belongings in El Paso. Raul Marquez echoed the pain, noting there is “no explanation” for why Sydney didn’t return to her hotel despite being captured on surveillance video heading in that direction.

New footage obtained by investigators shows Sydney walking calmly just 150 yards from the hotel in southwest Houston’s Chinatown area, near the 9100 block of Bellaire Boulevard. She was last seen around midnight, wearing gray pants, a gray hoodie, and tennis shoes. Her vehicle was later found abandoned nearby, with keys and her cellphone inside—items her family says she would not typically leave behind.

Concerns for Sydney’s safety are heightened due to her diagnosed bipolar disorder, sometimes accompanied by schizophrenic features. Family members revealed she had not been consistently taking her medication at the time of her disappearance, which could have influenced her behavior. Raul Marquez mentioned that Sydney had wandered off alone in the past, and on the night she went missing, she reportedly took a friend’s car briefly before leaving it running and walking away.

The Houston Police Department is actively investigating, with support from volunteer organization Texas EquuSearch, which has deployed resources and volunteers. Immigrant advocacy group FIEL has also joined efforts, encouraging witnesses in the diverse southwest Houston community to speak up without fear of immigration repercussions. “If you see my daughter, if she’s endangered, please don’t stay quiet,” Raul pleaded. “If you see something, if you know something, please say something. I miss my daughter. She needs to come home.”

As weeks pass without breakthroughs, the Marquez family remains in Houston, refusing to give up. Describing the ordeal as a “nightmare before Christmas,” they emphasize that time is critical. Tips have been followed, including potential bus sightings, but none have panned out yet. Sydney, the youngest of four sisters, was known for her drive and advocacy for others, graduating from Texas A&M in 2023 with dreams of helping people through her neuroscience expertise.

Authorities urge anyone with information to contact Houston Police Missing Persons at (832) 394-1840 or Texas EquuSearch at (281) 309-9500. The family hopes renewed public attention will bring the clue needed to solve this baffling disappearance and bring Sydney home safely.