Look, court and attnys and anything legal is scary stuff! Especially when its about a marriage and custody - two very emotionally charged reasons for needing an attny. Lets say you won 10 million bucks and retained an attny to protect you - that would be awesome but when you need an attny for something not so great, well, it adds lots of "ick" to the mix.
I would say to give your W space right now. She feels blindsided (never a good feeling), she might be scared, frustrated, nervous, upset and a whole slew of things. And right now, in her eyes, you created all those feelings by getting an attny and her not knowing about it. That is not to say you did anything wrong by retaining counsel for protection and guidance but right now its doubtful she will see it that way. Anything you say or do right now is just going to add fuel to the fire and create more negative feelings IMO.
Maybe you can talk to your attny about the best approach to use. For example - if your W does not have counsel then I think the attny would have to contact your W directly. And maybe your attny can use an approach that really gets the message across that you would like to keep things friendly and amicable. Who wants to get in a legal war? NOBODY! But right now your W feels blindsided so she will go to self protection mode.