Ok, some questions here you may or may not be able to answer:
Who was the last person to talk to her before she was reported missing- in person or on the phone, not texting. We've heard of cases where a perp texts as the person to loved ones and friends.
Did she disappear from her home? If so, was there anything that sent off red flags- such as a sign of a struggle, door wide open, animals not being tended to?
Was there an ex in her past that was violent? Did she have kids, and if so, was there a custody battle or threats made to her because she left him?
Any signs of a struggle outside- by her car, by her door, dragging marks?
Did she work? If so, did she show up on the day she went missing to work?
If I think of any more, I will post them later. I hope and pray your friend is ok. I'll do whatever I can to help.