My girlfriend says she has no phone signal but appears active periodically on Facebook mobile. Is she lying?

[masterpastry]

My girlfriend stopped talking talking to me for several days, ignored me for days on end through Facebook, Text and phone calls. She even blocked me from reading her facebook posts. Anyway, she finally talked to me and told me she was sorry and that it was due to stuff going on that she was too embarrassed to tell me about concerning her losing her job and needing a new place to stay. She then told me she was going on a camping trip about five hours away from her home that has no phone signal at all and that she'll be unable to talk until she gets back in two weeks.

That's the background. She's more than shattered my ability to trust at this point, but here is my question. She has been showing up as "Active" on facebook messenger in the afternoon and late evenings. Is it possible that the app is messing up, or is she obviously lying to me?

I know it sounds like she's dragging me along, I'm not stupid. What I want to know though is if it's possible that she's not online at all and actually in an area with no signal at all like she says.
In response to the person saying I seem obsessive: She stopped talking to me for eleven days, blocked me from seeing her facebook posts and ignored my phone calls despite the fact that we're involved with a work project together that is supposed to be done by the end of the month. Then, once I did finally get ahold of her (by contacting a friend who just happened to be with her at the time I messaged), she told me she was going on a camping trip for two weeks in an area that was hours away from phone signal of any kind. I do believe a certain amount of distrust on my part is warranted.

Nevertheless, my question was if this could be Facebook being inaccurate and periodically marking her as online randomly, or if she is not where she says she is and has me blocked from seeing her.