There seems such high reliance on Terri's cellphone location as an indicator of where Terri was. Terri has been questioned about where she was driving during those critical 1.5 to 2 hours after Kyron disappeared from the school and massive searches have been conducted based on her cellphone pings. It would be interesting to know if calls or texts came in to Terri's cellphone during those critical hours and if so, were they were answered or did Terri not respond to them until closer to the time she went to the gym? IMO, this would suggest that Terri's cellphone was not with Terri during those hours but was instead with someone else.
During those same critical 1.5 to 2 hours, Terri's friend DS was missing from where she was to be working that day and she had locked her cellphone in her parked car during that time.
We know Terri used "misdirection" on the date of Kyron's disappearance. She claims to have last seen Kyron (the back of his head) as he entered the classroom at 8:45 am, but multiple witnesses reportedly claim to have seen Terri and Kyron together, walking to her Ford F150 closer to 9 am. Terri claims she told Kyron's teacher that Kyron had a doctor appointment on June 11 (a full week after Kyron disappeared), but the teacher believes that Terri told her June 4 (and thus wasn't concerned when Kyron wasn't present when she took the roll call). Kaine was led to believe Terri would be using the Ford F150 to pick up Kyron's science project on June 4 but Terri did not do so and claims to have sent an email to the teacher that day asking WHEN she could pick the project up. That's a whole lot of misunderstanding and miscommunication for a single day - and particularly when that day is the one where Kyron disappears (for 15 years so far).
IMO, Terri's inclination toward misdirection should be considered when deciding how much reliance to place on her cellphone and vehicle as indicators of her physical location during the hours after Kyron disappeared from school. Likewise, given how close they were, whether the oddities regarding DS's physical location that day were misdirection should also be considered (fellow workers at the farm couldn't find her for a few hours, she couldn't be reached by her cellphone, and she admits having locked her cellphone in her car during working hours). How typical was it of DS to leave her cellphone in her locked car rather than carry it on her person?
I think it very likely that DS was "impersonating" Terri during those 1.5 to 2 hours, driving the Horman's Ford F150 with Terri's cellphone and toddler daughter along for the ride during those 1.5 to 2 hours. DS wouldn't want her own cellphone with her at the time because that would reveal that DS was with Terri's cellphone and vehicle.
So, if DS was with Terri's cellphone, vehicle, and toddler daughter, then WHERE was Terri? We know she likely did not have DS's vehicle as it was parked with DS's cellphone at the farm where she was working.
So, what other resources did Terri have access to, relatively certain control over, and where - that would be adequate to make a 7 year old child disappear (for 15 years so far) without any witnesses seeing anything?
ETA: One question that should be asked DS (assuming DS's immunity agreement requires that she answer questions honestly): If Terri and Kaine were to divorce, did Terri expect that SHE would be the one gaining the family home and property?