C# sample code for find If Statements in string

This is my string:

    
        You're a child!
    
        You're a man!
    

    
        You're a girl!
    
        You're a women!
    

how can extract if else parts from this string with best performance?

I need to get

 
        You're a child!
    
        You're a man!
    

and

    
        You're a girl!
    
        You're a women!
    

and inside parts in this results