Our second child was born. I think I became more helpful, but not nearly as helpful as I should have been. Shortly after the birth of our second child, my W took a new position at a new company as a manager. It was her first real promotion. This is also the time that she started working under the OM (but that is a sidepoint). I was supportive of the move, but I believe there was some envy in me at the time as well. I helped out more, but it was always on my terms. And for some reason, I had some sort of anxiety over the babies myself. So to help out, I would go grocery shopping while W stayed at home and took care of the girls. W rarely got out of the house unless it was as a family or to go to work.
The new career definitely added more stress on her. She had an anxiety attack a few months after beginning it. I remember being in the emergency room at 2 AM praying that the screening for MS came back negative (the way the attack presented itself was the same as some of the MS symptoms). Fortunately, they said it was "just" anxiety.
Even though you didn't communicate this envy verbally, your body language probably did in subtle ways. You showed some insecurity on your part and this affected your wife who was really feeling insecure at the time and dealing with lots of anxiety which may be related to not feeling secure around you. She may be very sensitive to this one point and it seems you kept reinforcing that you couldn't or wouldn't provide her with the security she needed at the time.
