Oh boy. I generally don't weigh in on this type of thing because nobody should ever take advice from me, but there's a glaring point I have to mention.
In all of the things you've said about your wife in these posts, there isn't much that reads like you see her as a life-size human being. You've said she's crazy, she's hot, she's suspicious, whatever, but it all seems oddly dismissive of your wife the person, as opposed to your wife the hot crazy thing.
I understand we're only getting a sliver of the whole picture and I really don't mean to throw stones at you at all, but from the few sentences you've offered I can totally get that you love your kid but I don't get that at all about your wife.
It just makes me wonder if she's picked up on the notion that your appreciation of her is somewhat superficial, especially now that she sees you with your kid and sees what it looks like when you truly love somebody. If so, she'd have to think that your commitment to her will only last until her hotness fades and, having had a baby not long ago, she's likely been feeling that it already has to some degree. It's not such a leap to get to her suspicions, unfounded though they may be.
Before you write her off, try getting to know her with your blinders on and ride that out a while. Then she'll know you're with her for who she is and not what she is.
Sorry if all that sounded preachy or insulting. But I wish all three of you good luck and happy times as a family.