River Walker by Cate Culpepper

Any night La Llorona walks the river is a night to stay indoors. One moonlit midnight, two very different women meet on the banks of the muddy Rio Grande. Grady Wrenn is a cultural anthropologist, enthralled by a local ghost story about a vengeful spirit known as the River Walker. Elena Montalvo, a spiritual healer, is that tortured spirit's only defender. Together, Grady and Elena must find a way to end the River Walker's murderous vendetta-- and overcome a maze of cultural barriers to find each other.