A few devil's advocate responses:
The cops didn't appear to think much of the condition of the bed. Laina herself at one point indicated a slat or two may have been out of place, but the mattress wasn't turned over or in significant disarray. Bored little monkeys jumping on the bed earlier in the day could have caused it. Was the top sheet really missing from the house or just missing from the bed? No one has said. Did the two littlest ones take naps in that bed? I know she was preparing to make up a room for them, but it doesn't sound like that had happened yet.
According to weather records, the day was mostly overcast leading up to a stormy night. Laina didn't say how many lights were on, but it's a tiny house and "all" the lights probably weren't many. Now, if lights were on in the bedrooms and bathroom, that would be significant, but a couple lights left on in the living/eating area on an overcast afternoon may not be indicative of anything, timeline-wise. I'm curious to know what "all the lights were on" means in this context.
The only thing in the trash was a diaper from earlier in the day, and there's never been any mention of food preparation beyond watermelon in the fridge, so it's hard to say whether she prepared any dinner or not. House was on septic as I recall, which makes a garbage disposal unlikely. I don't think the contractor would have installed one during the flip. So if there really was only a diaper in the trash, I question whether she ate dinner.
SIL said there were no signs of struggle in the house, and LE seems to have not considered it a crime scene. Neighbors did not report any disturbances and in that neighborhood there's a high likelihood someone would have heard an argument or a scream. It's also interesting to note that neighbors expressed no fear for their own safety when interviewed by the local news and seemed instead to see it as an isolated incident. I'm not sure why they feel this way, unless they're convinced no violence or abduction happened in the house.