PHOENIX — Wednesday marks two years since a Glendale girl went missing and her mother is holding out hope of a reunion despite minimal clues on her whereabouts.

Alicia Navarro was 15 years old when she disappeared from her family home in the early morning hours of Sept. 15.

Police have since followed up on more than 300 tips — detectives traveled to Henderson, Nevada, in one instance — but Navarro hasn’t been found.

“I’m not giving up. I love my daughter,” Jessica Nuñez, Navarro’s mother, told KTAR News 92.3 FM.

There’s no clear indication why Navarro, who has autism but is high functioning, would leave without notice.

A day after her disappearance, Nuñez found a note on top of Navarro's desk. The note read: "I ran away. I will be back. I swear. I'm sorry."

Nuñez and police believe her disappearance could be linked to friends she met online, but nothing concrete has been determined.

“I’m just still in shock that she was willing to do something like this,” Nuñez said.

Detectives made the almost five-hour trek to Henderson after several reports of sightings of Navarro possibly at a homeless camp. Navarro wasn’t located during that trip.

“There’s just no trace of her and its unbelievable that there’s no clue or little shred of evidence to tell us where she is,” Glendale Police spokeswoman Tiffany Ngalula said.

Glendale police still receive about five tips a week in relation to Navarro, according to Ngalula.

Her 17th birthday is Monday. Nuñez wants her daughter to return and live out her dreams they had previously discussed, including going to college.

Anyone with information as to Alicia's whereabouts should call Glendale Police at 623-930-3000.

KTAR News 92.3 FM’s Griselda Zetino contributed to this report.