The Trigger class is:

trigger FAAsettingCurrentLimit on Request__c(before update) {
    for( Request__cparent: Trigger.new)
    {
        if((parent.Request_Status__c=='Approved') && (Trigger.new[0].Request_Status__c != Trigger.old[0].Request_Status__c)){
            List<Limit__c> children = [ SELECT Id,Name,FAA_Request__c,Current_US_Dollar_Limit__c,Desired_US_Dollar_Limit__c from
            Limit__c where Request__c= :parent.Id];
        
            List<Limit__c> childrenToUpdate = new List<Limit__c>();
        
            for(Limit__c thischild: children )
            {
                thischild.Current_US_Dollar_Limit__c =thischild.Desired_US_Dollar_Limit__c  ;
           
                childrenToUpdate.add(thischild);
        
            }
            update childrenToUpdate;
        }
    }
}

There are two objects ,object 1-Request__c and object 2-Limit__c

The test class for this trigger class is

@isTest
private class FAACurrentLimitTest {

static testMethod void myUnitTest() {
Request__c[] faalist=[select id,Request_Status__c,Agent_Redelegate__c,Delegator_Approval_Status__c,
Delegator_Name__c,Delegator_Status_Date__c from Request__c limit 1];

Limit__c CategoryLimit=new Limit__c (Category__c = 'Treasury',
Desired_US_Dollar_Limit__c=100.00,Current_US_Dollar_Limit__c=120.00,Request__c=faalist[0].Id);
insert CategoryLimit;
Limit__c[] clist=[select id,Category__c ,Desired_US_Dollar_Limit__c,Current_US_Dollar_Limit__c,
Request__c where id=:CategoryLimit.id];
clist[0].Desired_US_Dollar_Limit__c=120.00;
update clist;


}
}

But its Showing error in (:CategoryLimit.id) and

if i remove that line the trigger name itself not displayed after running the  test class.