Efficient XML Parsing

I'm working with the XMLSOCCER API which produces an XML response with the data.

They have a .NET library to work with their data.

var x = Client.GetAllLeagues(ApiKey);
XmlNodeList list = x.ChildNodes;

GetAllLeagues(string ApiKey) returns an XMLNode which is the root of the response:

<?xml version="1.0" encoding="UTF-8"?>
<XMLSOCCER.COM>
   <League>
      <Id>1</Id>
      <Name>English Premier League</Name>
      <Country>England</Country>
      <Historical_Data>Yes</Historical_Data>
      <Fixtures>Yes</Fixtures>
      <Livescore>Yes</Livescore>
      <NumberOfMatches>5640</NumberOfMatches>
      <LatestMatch>2015-04-13T21:00:00+00:00</LatestMatch>
   </League>
   <League>
      <Id>2</Id>
      <Name>English League Championship</Name>
      <Country>England</Country>
      <Historical_Data>Yes</Historical_Data>
      <Fixtures>Yes</Fixtures>
      <Livescore>Yes</Livescore>
      <NumberOfMatches>8335</NumberOfMatches>
      <LatestMatch>2015-04-17T20:45:00+00:00</LatestMatch>
   </League>
</XMLSOCCER.COM>

I can get to the Nodes and their values with the following:

for (var i = 0; i < list.Count; i++ )
            {
                var children = list.Item(i).ChildNodes;

                for(var j=0; j < children.Count; j++ ){

                  Console.WriteLine(String.Format("Key:{0} Value:{1}", children.Item(j).Name, children.Item(j).InnerText));

                }
            }

The problem I'm facing is that this feels largely inefficient. If I could use XmlReader it might make it easier to work with. But since XmlReader.Create(); Expects a Stream, I can't work with the XmlNode that the API returns.

I thought I could use the example from the following: http://ift.tt/1GYQ2GA

How would you parse the data?