Did we watch the same trial? Jeantel's testimony was a train-wreck. Beyond the personality stuff that I'm not interested in, her actual statements are a mess: didn't report until weeks later, wasn't forthcoming with details originally, what details she was forthcoming with changed substantially over time, lied numerous times to attorneys about her age, lied in her deposition.
All humans suck at recalling memories accurately. Every time we access a memory we overwrite it, so memories evolve over time despite our best intentions to preserve them. It's imperative to have clear, detailed statements from the immediate aftermath of something like this (and those are usually pretty spotty in quality still). The fact that her testimony changed so much after coming in late is a big warning sign.