She's now 9 years old and while she's been a blessing to us, she's also much more challenging than our biological son. For example, she has a strong personality, including being very hot-tempered (I shudder to think about what her teenage years will be like).
Put in religious terms, she seems to have a more rebellious nature than our biologial son. And, while it would devastate my wife if she were to someday leave the church, I try not to think too much about that and, instead, focus on us giving her a better life than she probably would've otherwise had.