It seems as if she does fine up until her serve gets broken, then the white flag is unfurled and the floodgates open for the rest of the set. Hell, even if she's ahead a break in the set, if she gets broken, the floodgates still seem to open.
Pretty much this.
She gets rattled, and then becomes overzealous.
Every single shot she tries to rifle for a winner... she needs to pick her spots a lot better. I admire her tenacity, but it's almost as if she's bought into the hype a bit too much... like people have told her when she's down, she can always just hammer her way to the top.
She's not Serena.
I was the same way when I played competitively (was nationally ranked as a junior at one point, though many years ago)... I did the same thing. I had a crazy forehand winner that I thought was my ace in the hole... so every single forehand I got, I tried to smash it down the line. It worked... sometimes... until I realize I was costing myself a whole ton of points based on unrealistic shots.
Overall though, she has to make a choice - she's either gonna choose to be a hot piece of ass that plays tennis, or she's going to be a world class tennis player. The way things ended with Savarino spoke a great deal to her mindset. She needs to beg his forgiveness, beg him back as her coach, and take a couple of tournaments off to find her game.