YA fantasy series, young priestess, child-god

I read this three- or four-book series a couple years ago and though I remember some of the main events, the titles and author are a complete blank. I believe it starts with a young priestess performing some kind of public rite (I think her name might be Miri or something similar, but no, this is not Shannon Hale's Princess Academy). There is a young boy who is a god and he is unpredictable; it's sometimes unclear if the god really is residing in him or if he's just being a brat. He might have been the prince. I remember a desert journey... and that's about it.

I didn't really love this series, but it irks me to have no idea who the author is. Thanks for your help!

Could it be the Oracle Prophecies series by Catherine Fisher? In the US the first book is title The Oracle Betrayed, and in the UK it's just The Oracle.

Sara, I think it is! Thanks very much! Now this doesn't have to bug me :)