ALOHA, Ore. -- The search for a 25-year-old Aloha woman whose family reported her missing last week has been suspended, police say, because they believe she left "on her own volition."

The Washington County Sheriff's Office, which has been searching for Emily Hooper for the past two days, said in a news release that Hooper "is an adult and has the right not to contact the police or her family until she chooses to."

Hooper's family reported her missing after she didn't return home after a Thursday night class at Portland State University.

Hooper lives with her father, who told KGW on Monday that her disappearance is out of the ordinary. "She's outgoing. She's fun. She has a good sense of humor. She's a good kid," said Emily's dad, Frank Hooper.

"I'm hoping for the best, but this is a long time. This is not like her. She doesn’t leave and not communicate anything with family," Hooper said. "It's awful. But I don’t want to think the worst. Got to think the best."

Frank Hooper said his daughter's boyfriend also called the family, asking where she was. He added that family and friends are doing the best they can, and they hope that someone will know what happened to her.