Are there reasons why a wife wouldn't get a 50/50 share of assets ?

There are circumstances under which a split would not be 50-50 - but keeping financial secret does not work.

This question doesn't really provide enough information. If you, as the Wife, did not pay the mortgage (because you maybe were taking care of the kids and running things at home, but not working), your contribution is still valuable, but it may not rise to 50% ownership of the marital home. Certainly you would be entitled to your marital share of pensions. Really, more facts are needed to assess the assets you are talking about. Consider talking to some lawyers near you to get a better feel of how they would approach your case.