P.C. Cast 
Divine by Mistake [EPUB ebook] 

I get this bizarre mirror world filled with a horse/guy who I have the serious hots for, creatures who are terrorising civilisation, deodorant-less armpits that probably stink and no toilet paper. This sucks. The only excitement Shannon Parker expected while on holiday was a little shopping. Finding herself flung through fire into the world of Partholon (and left with a massive headache, thank you very much), she’s now being treated like a goddess. Somehow Shannon has stepped into another’s role in another world.And while there’s an upside – who doesn’t love lots of pampering? – it also comes with a ritual marriage to a centaur and threats against her new people. Can Shannon survive this new world and ever find her way home?