I'm starting to think perhaps it wasn't her who sent the text from her phone.
Her friend stated that the text at 1:30AM (approx) from Hannah said she was lost and then gave the street/neighborhood and her friend thought it was odd since it's an area Hannah knows, and the same area where the party was.
I can't help but think perhaps someone abducted Hannah, then saw that her friends were texting her and responded to them that she was lost in an effort to throw off her friends, police, etc. and the abductor didn't know she had just been in a party in the same area so when her friend asked "where are you?" or something the person with her phone responded with the area she was taken from to match up with the area her cell was pinging in.
Sorry if that makes no sense. It's late and I'm tired. But the bottom line is I don't think Hannah sent that text.