Partholon (5 Book Series)

From Book 1:

The only excitement Shannon Parker expects while on summer vacation is a little shopping. But when an antique vase calls to her, she finds herself transported to Partholon, where she's treated like a goddess. A very temperamental goddess…

Somehow Shannon has stepped into another's role as the Goddess Incarnate of Epona. And while there's an upside—what woman doesn't like lots of pampering?—it also comes with a ritual marriage to a centaur and threats against her new people. Oh, and everyone disliking her because they think she's her double.

Somehow Shannon needs to figure out how to get back to Oklahoma without being killed, married to a horse or losing her mind….