There are two iron arrows (000D9B79, 000D9B7A) floating in the water near Reyda's corpse. The cause of her death (after FreeformIvarstead02) is inconclusive. However, based on the proximately of the arrows to her remains, it's rather obvious that they're supposed to be a clue.
One of the two arrows (000D9B7A) is flagged to respawn, which is probably a mistake.