I'd been eagerly awaiting the 1st issue of this relaunch.
My initial impression is that it's cute and full of charm, and I'm loving Sophie's new, cleaner art style, but...there's something lacking, and I don't quite know what it is.
I'm not into the Ninja Turtles, so I didn't read Sophie's writer/artist run on that series. Which leaves me with nothing to compare her Supergirl writing to.
Maybe it's more the editor's fault than Sophie's, because the most noticeable fault in the script is how continuity-unfriendly it is to readers like me, whose only prior experience with a Supergirl series is Peter David's run from 1996 to 2003.

I'll keep supporting Supergirl for now, at least until the Legion relaunch, whenever that turns out to be.