It would have to be a very -very- strange scenario for me to be anywhere without my cell, I haven't left home without it in years (sucks how dependant my life has become to that stupid device.) And in reality, the only place I can actually think of where it would be impossible to find a phone to borrow would be if I was out camping in the woods, and then I am not stupid enough to camping alone. All in all it is very difficult for me to think of a scenario where all of these conditions are true.
But in the interest of playing fair, attempt to wake her without touching her (ie. a loud noise) failing any response, I would check for any obvious signs of injury (lacerations, blood pooling, bruises, etc.) not finding any of those, I check her airways, clear them if need be, then her breathing, and circulation, move her to the recovery position, preferrably wrapped in my jacket to prevent heat loss. then either start banging on doors, flagging vehicles, yelling. But, we are assuming no human contact here, so really I would set up camp there, with a fire, and hope she wakes up.