older children issues

Hi, I wonder if anyone can assist. We have just started our adoption process for Colombia, We already have a 3 year old daughter from Guatamala, she was 8 months old when we brought her home. Owing to our ages (50) we will be adopting an older child. Do all older children have attachment issues ? Obviously, we are concerned about the family dynamic. Feeing quite bewildered with it all as when we adopted from Guatamala we had friends who had done it. We live in UK and don't know anybody who has adopted from Colombia let alone an older child.