Since it doesn't sound like much has been confirmed, I'll just post my possibilities and hope one of them is fitting.
If she never made it home, I wondered if someone stopped by her, and without her corrective lenses, she thought it was someone she knew and approached the car. I know that before my surgery I couldn't really see features on most people's faces without my glasses on. It's possible that she had the same problem if she couldn't see well without hers (which I believe her mother said.) By the time she realized it wasn't who she thought it was, she would likely be caught completely off guard and easy to throw into the vehicle. I'm not going any farther than that with my imagining...
If she did make it back to the house, she may have let the dogs out while she took a quick shower, let them in and locked them downstairs and started heading to her mother's place for dinner/supper/whatever they call it there!, and just left her stuff there because she planned to be back soon. I have no idea where the one witness lives, but I know the one who said he saw her earlier was a neighbor. Is it possible that both people were right about what she was wearing, but the first one was wrong about the time? If she went for her run around 7:30 and got home around 8:00 wearing the black sports bra, after he shower, etc., she may have left at about 8:30 wearing the pink one. She might have been running a little late and decided to jog at least part way (not enough to really break a sweat, but enough so the witness would describe her as running.) If so, the same thing could have happened that I described if she didn't make it back.
If she made it back and was still there until after 10, I'd have to guess that someone either followed her inside when she got back (with or without her permission) or someone showed up shortly after she got there but before she could leave for her mother's. If she was there alone between 8 and 10, I believe she'd either go for brats with the family or let them know she wasn't coming. I'd also expect her to be wearing glasses or contacts if she was going to be sitting around watching tv, reading or playing games/texting on the phone. Even if she fell asleep without eating, something would have to have happened very early since she doesn't seem to have canceled any ride to work she may have had set up. I still don't understand why whoever was supposed to bring her doesn't seem to have mentioned to anyone that she was a no-show.
Sorry for another novel. MOO