"Before we got married, we agreed that we would want our child to be cared for by a family member, or by one of us."

Amy, this is something they mutually agreed to. The fact that her husband is caught off guard by her being the breadwinner means that he expected his wife to be the caretaker by default. This is a huge red flag and doesn't bode well for their future. Even if they both continue to work, this default expectation will likely translate to more work for her - even though she's the breadwinner. The LW needs to postpone the baby talk and go to counseling. She and her husband are not on the same page when it comes to having children - they never were and he wasn't honest about this.