Troubled Waters by Sharon Shinn — book slip

Zoe Ardelay receives shocking news: she is to become the king's fifth wife. Unwilling to accept this fate, she escapes to the riverbanks, where she discovers her true identity as a 'coru prime,' with control over water and blood.

As Zoe learns to harness her powers, she must navigate the treacherous waters of court politics and decide how to use her abilities to uncover family secrets and assert her place in a society governed by elemental affiliations.

First in the Elemental Blessings series.