I mentioned this several threads back but worthy of re-post:
I believe LE initial impression that Mollie was doing homework late in the evening was based on incomplete analysis or misunderstood forensic digital time stamp of probably both her computer, and the University server she logged into. The Epoch, Unix, UTC, etc. encoding of digital analysis is beyond the scope of this post, but clearly it's complicated, and not usually reported in "real time." Nearly every trial today includes a mobile phone or internet analyst discussing the towers, pings, texts, etc. where you will often hear them explain to add/subtract hours from their report to adjust to local "real time." In other words, the forensic tools try to use a "universal time stamp," followed by adjustment to report the local timezone. Accordingly, I believe Mollie worked on homework earlier than LE reported to her brother, and witness (unconfirmed by LE).
I think Mollie arrived BF house at 5:30p, dealt with Dogs, and worked on homework between 5:30p - 7:00p ish, and left for her jog -- intending to stop at Mum's for brat and collect the car. I think Mollie disappeared before reaching her Mum's, and did not ever return to BF house. MOO..
Late Edit to add: I find it highly suspect that if Mollie was at BF house in late evening, that she made no family contact, and engaged in no social media, other than the single SC to BF, that we know of. So out of character ....