You will find no answers here, to your own thing. Talk to her.
Did you ever talk to her about this?I also probably have no business commenting on your choices, but if the two of you are having a hard time with just one child it probably wasn't the best idea to agree to adopting a second.
She might be cheating on you. That, or the reality of raising a child has hit her and she thought it would be easy.The kid's adopted, right? It might be she doesn't want an adopted kid.