What you wrote about your in-laws - pretty much a carbon copy of my in-laws. Said parent, in this case the mother, never really properly matured, so they are still looking to get their needs met in immature ways. So the children are always alert to please mother, often preoccupied with this at the expense of their own needs. Hard to develop a strong sense of self in such an environment and could lead to an identity crisis later on. As my therapist put it 'it's very hard growing up with a narcissist parent' (this could be an understatement). This realisation, and related emotional neglect, is perhaps, what your wife is confronting now and it's sad that you are collateral damage in her search for herself. IMO, there's not much you can do but let her find her own answers. Be yourself, because that is who she has loved for a couple of decades, and I doubt that you have changed dramatically. Keep being a stable force and a great dad for both your kids, that's all you can do.