The remains belonging to the 24-year-old were located in the Northern California town of Plymouth in Amador County on Thursday, and the identity was confirmed Friday by a forensic odontologist.
Gabe, a resident of Oakley in Contra Costa County, disappeared on Jan. 26, where she was last seen leaving the Antioch home of her former boyfriend, Marshall Jones.
Her car was found in Oakley but there was no sign of her.
Investigators say they determined Jones drove to the area where Alexis' remains were found in the hours following her disappearance.
Jones was killed in a Seattle suburb in June when police moved in to arrest him.
Gabe's father, Gwyn Gabe, posted to Facebook saying that the celebration of life will be held in Oakley on Jan. 28, two days after the one-year anniversary of her disappearance. The family will announce the venue once it is confirmed, but can only invite 250 guests. Once they create an event, those who want to attend can reserve a spot.
They also have a community candlelight vigil scheduled for December 9.
"I hope you can come pray with us. Alexis would appreciate your presence that night," Gwyn Gabe's post said.
Officials say a press conference will be scheduled for early next week.