This will create an extension on top of IWebElement that will let you call GetParent directly on the child IWebElement
public static class MyExtensions
{
public static IWebElement GetParent(this IWebElement node)
{
return node.FindElement(By.XPath(".."));
}
}
Example usage...
IWebElement node = WebDriver.FindElement('..');
IWebElement parent = node.GetParent();