BD:
If the baby is only 4 months old, would your wife be reacting due to stress - both of her faith and having a new child to care for??
Your announcement could put her over the top if the baby is causing her some anxiety post nataly.. for some people, faith is life, and if you lose your faith in the org, her "head" is gone spiritually, maybe a lot of things are going thru her mind, how can she bring up the children in the "faith" by herself - no husband to study with them, to help her at the meetings, to help her in service, to be able to attend a party or get togethers for the family, all the things a Spiritual head can do - give her some positive feedback - you will get her to the meetings, you will be there for the kids and her - she wont be alone in this but your transition from the org is something you both have to deal with and come to a neutral stance to save your life -post org.