Okay, I did suspect, from what you said, that she was somewhere on Mindanao. Yes, there are very remote areas well within 4 hours travel from Davao.
We have a friend here who was working away from home - even his wife had not heard from him for three weeks and had no idea when to expect him home, when he turned up one day.
Likewise, my father-in-law visits his farm 'at the mountain' and we have no contact from him for a week or more.
Indeed ... parents might tell her that even if she has no local b/f - indeed, many friends and family almost convinced Ruby that she wouldn't see me again after my first visit. The respect within families here would almost compel her to comply. Perhaps she can only attempt to chat with you surreptitiously, while none of the family are around.
I'm sure that you were aware of how many beautiful Dabawenians were giving you admiring glances while you were here - if the worst does happen, get yourself back here and try again!