Left on her own is inconsistent with the few facts we know. Here's what I have so far:
- KB and child went to Safeway around 12:30 MST on 11/22, as evidenced by store video.
- Her cars were parked in her driveway as of 12/2, as reported by her brother.
- Her suitcases and cosmetics were not removed from her home, as reported by her brother.
- Her purse and cell phone are missing, too.
- PF has the child that KB was last seen with.
- KB's phone sent two texts on 11/25, one to her boss and one to PF
- CB, KB's mom reported her missing on 12/2.- Phone ping in Gooding, ID on 11/25 at 5:13pm
- Cinnamon rolls were left out on the counter
If she left on her own, she left with her purse and without her child or her two cars. That implies that PF did indeed "pick up the child" (or she dropped her off). So yes, another person is remotely possible if you believe 1) that on her day off, KB voluntarily left K in the care of PF, and 2) she left home with only her purse/cell phone (how?) and not her cars/makeup/fresh cinnamon rolls.