My opinion, my own opinion, just sayin'...
I'm trying to figure out how a 13-year-old girl could be "in hiding" for this long.
I think it's too cold to be living in someone's garage or tree house or shed. Besides, there's the problem of toilet facilities. Thirteen year old girls tend to prefer flush toilets.
I could understand maybe staying with a school friend and sleeping under the bed and having food sneaked in, and ~maybe~ adults being none the wiser...but not for more than a day or two.
Even if all of the adults in the house were gone all day, there'd surely be signs of more food being gone, more trips to the bathroom in the middle of the night, more dirty clothes (assuming that the friend was lending the "visitor" clothing), just general evidence that there are more people in the house than normal.
Could she be rotating between friends so as to stay hidden? Maybe, but she'd be taking quite a chance of being seen between hiding places, especially if the community is on high-alert as that one is.
Could a person live in a home without adults noticing? Well, I'd like to say not in my house, but as far as I know, none of my daughters have ever tried to covertly harbor a runaway.
I ~hope~ she's hiding, but my innermost thoughts are disagreeing.
As for the "no telephone number for mom", well, the child ~is~ thirteen years old, I'd bet that she has more than mom's cell phone number memorized. We made sure that our daughters, by the time they were in kindergarten, had three phone numbers memorized - Mom's, Dad's, and a family friend's. Even given that this is the cell phone age and you select a name rather than punching in a phone number...nah, she ~has~ to have some numbers memorized.
My opinions only.