How do I help wife with sundown scaries?

Our baby is a week old, my wife is getting “sundown scaries.” We’ve been splitting the night into shifts- I get four to six hours of sleep so she can get 8 or close to it, plus a nap during the day when she needs it- she has 2nd degree tears from the birth on top of normal healing, so she needs more sleep to heal). That means I go to bed at 8 and get up at 2. However, when I’m getting ready to go to bed, she starts crying and gets upset. She’s a good mom, super knowledgeable and capable. She won’t tell me what’s wrong or what I can do to help and just tells me to go to bed. She says she’s going to feel that way no matter what. I’ve been doing the chores (enough to get by) and we prepped a bunch of food so she doesn’t have to cook, do laundry, clean, etc. she can focus on healing, taking care of the baby, and whatever else she needs. I’m capable of taking care of our daughter on my own so we’re splitting the load pretty easily. She breast feeds and pumps, I feed with formula or stored breast milk. But I don’t know how to help her in the evenings, and I need to get at least a little sleep. Does anyone have any experience with sundown scaries? Anything I can do to help? Any suggestions?