Caroline has definitely made improvements on speed, as well as conditioning (in her core strengths especially) -- though she did slow down in the second half of the FS, especially right after missing the second 3F, when she looked momentarily surprised and frustrated.
Considering how much extra weight she's carrying now compared to a couple years ago (while at the same height), the fact that she's skating a little faster means that she has actually improved a lot on speed. If she skated now like she used to, she should be moving half as fast! I mean that from a purely biophysical point of view, not intending to be mean or anything. If she could slim down a little, then the improvements she's made in speed & strength would be even more apparent to the eye.
Maybe most of that extra weight she's carrying now is muscle, but there is a different optimal body shape for each sport. That's why top athletes in boxing, swimming, and skating look completely different even if they are all very "fit" in their own way.
She's taking a year off school to focus on skating this year, so hopefully this means that she can really get into tippy top shape. She may be rather unlucky when it comes to genes, but I also remember she always had a sweet tooth and didn't do much off-ice training until very recently.