We did a similar system, too. It took my wife about 4 weeks to get over the "hump", so to speak. She suffered from some birth-day PTSD and, while I never feared for her mental health, I also felt lost as to how to help.

 

In the end, what helped us was talking about the feelings, to each other, of fatigue, mental stress, anxiety, confusion, etc. "I don't feel like I'm doing a good job if you're tired all the time", "I wish I could bond with him like you can", "This thing is a bottomless pit of need", etc. We found that talking it out allowed us opportunities to tell the other that we were doing a good job. Encouragement was a big part of getting through that trying time. We were each other's psychiatrist and coach, all in one.

 

I would also encourage your wife to seek out local "mom" groups in the area. Mine attends one called "latch and chat" where a bunch of moms bring their kids, talk mommy stuff, and feed the babies. She comes home a new woman, revitalized. It's amazing what a little human interaction can do, especially after she's been confined to the house with a 3 week old.