I have a pretty decent theory. I started to type it out earlier but the darn phone froze and I lost everything. I'm too tired to type the uber detailed version, so here's the shorter version.
Perhaps she and a friend of hers (I have one in mind but won't name names yet) became intimate, either consensually or forced, days prior to her disappearance. The plan b suggestion would actually fit here then. If said friend were obsessed with her and wanted her to love him, he might get angry if she says she's going to take a plan b pill (it would be too early for abortion talks at this stage). So he takes her credit card from her and cuts it in half so she can't purchase said pill. Fast forward a couple of days. She asks dad for $ because mom would ask too many questions. Dad, on the other hand, is being extra nice to the kids because of the recent separation, so he loans her money, no questions asked. He gives her too much in fact, but what teen is going to turn down extra money?
She goes back to the house so pops doesn't get suspicious. Then, once she thinks pops has returned to work, she drives back out to the pharmacy, gets what she needs, then drives home. The friend ends up showing up shortly after to talk to her. You can take it from there.
This is alllll speculation. But I have reason to suspect she was with a certain friend that weekend prior to her disappearance. And this may be the same friend who just happened to find a piece of her card. There's other reasons why she might ask dad for money out of the blue like that, or maybe the money borrowing never actually occurred - who knows. But I'm just trying on different goggles for a moment to see if any fit....
and what may be a reasonable solution to them makes no sense to us.
