How to show child query count in lightning component in Salesforce?

Hi,

You can try below code to show child query count in lightning component in salesforce:-

List<Account> lstAccount = [ Select id,name,(SELECT id,Name From abc__Site__r ) from Account ];
	For ( Account acc : lstAccount )
	{
	     List<SVMXC__Site__c> lstSite = acc.abc__Site__r;
	     if( lstSite.size() > 1 )
	     {
	        System.debug('More then one site');
	     }
	}

For more:-https://developer.salesforce.com/forums/?id=906F0000000DBc6IAG