Urban fantasy as a genre is pretty much pure entertainment with few works striving to be more, but even with most of it being fluff, there are some that are much more lightweight than others. The works of MaryJanice Davidson fall into the ladder category, amusing but mostly forgettable stuff. Characterization is utterly rote, plots are an afterthought and the prose is merely serviceable.
The Fred the Mermaid trilogy is about a female half-human, half-mermaid hybrid who has secretly lived among humans and gets involved with other mermaids and has three books to decide between a human and a mermaid love interest. She’s established as snarky and abstinent, but her stick (as well as that of all the other characters, who are just as one-dimensional) is only tolerable in small doses (maybe that’s the reason the books are so short).
As said, plots are an afterthought and utterly perfunctory. The worst offender in that regard is probably the second book, whose plot is summarized as, and there was a big meeting and then a decision was made. Yep, that’s pretty much it.
Another example why this is really fluff is the way Davidson handles her characters and how they react to major trauma. SPOILER ALERT In the last book Frederika goes from being all cuddly with her long-lost dad to breaking his neck once he reveals himself as a big bad. Instead of any psychological turmoil after that or at least a decent human reaction to having killed someone, she shows no sign of being at least a bit stressed out about that. Sure, there are people who react like that, but I somehow doubt Davidson intended Frederika to be some kind of sociopath.
It’s kind of odd, these are books based almost exclusively on the interactions between the characters, their conversations, not action, scenery descriptions, backstory or deep introversion. It’s all talk, talk, talk, but while most of it can be described as amusing and entertaining, there’s no depth to it. Characters remain one-note, and occasionally, as with the few kills that happen, characters react weird (and that’s a nice way of saying that author Davidson has only a perfunctory grasp of how to write realistic human beings once it goes beyond snarky, superficial dialogue).