Hi Chrome, finally got to this thread. No, I'm not mad. Just keep your mind open. This relationship/soul/identity is not rocket science-- it's MUCH more complicated!
After reading the Brooke Shields book "Down Came the Rain" about her postpartum depression, I'm wondering if your W might be going through something like that. There is so much pressure on new moms to be a certain way and feel a certain way, to be competent right away at unfamiliar tasks, etc. Add to that the pressure to be a fully present wife and lover-- it's no wonder women are driven to the breaking point. And Brooke only had one-- y'all have three. The way you describe being at home and overwhelmed by the babies-- just think, she has been there all day.
Brooke felt so awful, and felt doubly and triply awful for feeling so bad-- she felt such shame and such a failure, not only because of the way she handled tasks, but shame over the way she felt. She NEVER expected to feel so bad... it's a wonderfully written book and brutally honest. Her depression put a tremendous strain on her husband and on the R. Something to think about.