Lucky's Treasure.

When college-bound Emily Landis moves from the city to her grandpa's country home, she is expected to take care of Lucky, her late grandma's horse, and makes it her mission to show the light of Christ to her grieving grandpa. Emily is befriended by a local named Jake, and when the two discover Emily's grandma died searching for hidden treasure, the pair attempt to find the rare gold coin that has eluded treasure hunters for decades.