Well… since you value my opinion, here is some more advice. Let’s say your older kids are named A, B, C, D, and E. Once you adopt this child, you need to refrain from comments such A has his grandfather’s nose, B has her aunts eyes, C, D and E have these characteristics from other relatives. The 6 child will not have any resemblance to other members and those comments will cut deep. Yes, I got the short end of the stick but I still can have sympathy for the adopt kid.
Next, depending on the age the adopted kid, this may of may not be appropriate. Nonetheless, here it goes. If you have a routine, for example, no eating in front of the TV and the adopted kid comes from an atmosphere where eating in front of the TV is allowed, you can not take on the attitude ‘This kid is new to my family so I will let her eat in front of the TV’. That will make the other kids resent her. The rules are the same for all 6 kids. So unless you are willing to let the other 5 eat in front of the TV, they I would NOT let the new kid practice her old routine.
My cousin and his wife adopted two kids internationally since they could not have their own. The wife just wanted to be a mom. She thought these kids would worship the ground she walked on for bringing them out of the poverty of an orphanage:banghead:
The first English the little girl learned was ‘I can’t wait to be old enough to go back to Europe and live with my really mommy.’ So what did the wife do??? She complained to everyone about how ungrateful this kid was

Don’t be surprised if this kid eventually accuses you of not loving her because she is not biological. Just tell her that you really wanted an other child and after reading all the profiles you chose her and then name the qualities you like in her. And if the truth of the matter is, the agency gave you a child and you had no say in the matter… tell a little white lie and tell this kid she was chosen for her and then go to confession