They are looking for clues to her dissappearance from her Facebook account.
Bethany Anne Decker, 21, has a 17-month-old son and is believed to be about five months pregnant. She was last seen Jan. 29. After weeks of failing to contact Decker, her family reported her missing Feb. 19.
Authorities said she was not immediately reported missing because Decker's Facebook account seemed to be active for some time, although her family had not been in direct contact with her.
"I'm praying and I have faith that she's safe," said her mother, Kim Nelson. "Wherever she is, she knows that we love her."
Investigators said they have no idea what happened to her. Her car was found at her last known address on Orchard Grass Terrace.
The sheriff's office is looking at all possibilities, including foul play, though there is no evidence of any at the moment.
"She's one who would be texting us, calling us," Nelson said. "If she wasn't talking to me, she'd be talking to one of her siblings."
Decker, a senior at George Mason University, is white, 4-feet-11-inches tall and about 130 pounds. She has brown hair and brown eyes.
"He has been here in the country on leave, and was with Ms. Decker back in January," said a member of the Loudoun County Sheriff's Office. "We need to come up with a timeline as far as their contact with each other before he was sent back to Afghanistan."
When Decker wasn't at her husband's Feb. 2 deployment sendoff, that was her family's first red flag. Another was the fact that her car was parked outside her home but she couldn't be reached. And her family doesn't believe she'd choose to be separated from her son.
Law enforcement officials said they spoke to Emile Decker and were trying to arrange an electronic face-to-face follow up interview with the military's help.
The sheriff's office said the last person to see Decker alive was a boyfriend. The office said the man has been cooperative in the investigation.
Anyone with information about this case should call 703-777-0475.