I'd read the first of these two books (The Native Star) a while back and re-read it again recently in preparation for reading the second (The Hidden Goddess) - the storyline for the second pretty much runs straight from the end of the first one.
In both, the focus is on our protagonist, Emily Edwards, who we first meet in a small town in California. Emily is a witch, what's called an animancer as she uses the powers of nature to do small magics; when we first meet her she's just made a significant mistake in using those powers to make a local man fall in love with her so she can guarantee future security for herself and her adoptive father. She then spends much of The Native Star angsting about this in a way that I found more than a little anachronistic for the time period in which these books are set - women have historically done much worse for less understandable reasons.
Meanwhile, there's also another magic practitioner called Stanton hanging around town, one who Emily ends up going on the run with after she ends up with a magical stone (the eponymous Native Star) embedded in her hand and all sorts of folks trying to get hold of it. Naturally, in the middle of all this, Emily ends up falling for Stanton and the beginning of The Hidden Goddess finds the two of them engaged and in New York, where Stanton is taking over the reins of the magic institute of which he is a member.
A lot of The Hidden Goddess is about discovering Emily's past, the parents who we now find she didn't remember because of magic her adoptive father performed to ensure that was the case, as her early childhood had been so traumatic. Meanwhile there's also an apocalypse on its way, as the various folks who practice magic and those who think it ought to be snuffed out are facing off.
Interestingly enough, I recently read something about genre which was all about the balance between world-building and characters, saying that the former was more important in genre than the latter, even if some (but only the most exceptional, apparently) could manage both. This series is definitely heavier on the former, particularly as we move from the first book to the second, with Emily becoming all but a cipher. The world-building is excellent, with clearly a significant amount of thought applied to it, but the story that's told within it just doesn't work for me, let alone convincing me that these two characters ought to be together long-term.