Gabby was supposed to meet her good friend at Yellowstone on August 31 for the friend’s birthday, so it was weird, and way too out of the way, for her to say Yosemite instead of Yellowstone in that last text, as she had told her Mom in the last phone call that those were her plans. That is partly why Mom never believed the text about Yosemite on the 30th was from Gabby. It may also have been the writing style, too, not sure about that.
Also, Brian got home to FL on Sept 1, but Abby wasn’t reported missing until Sept 12. Either Gabby’s Dad, or stepdad had had a conversation with someone about this (I think it was the police) on the night of Sept 11, and the next day she was officially reported missing. (These are birthdays in my family, that’s why I remembered the dates.)
(Shoot, I had some quotes on my phone but lost them on my iPad. May have to go back as there were some other things I wanted to respond to.)
I didn't know that she had told her mom that she was supposed to meet her friend at Yellowstone. That makes the Yosemite text very suspicious then.