Each to her own, but what did she contribute?
I can't imagine not sharing the joys and troubles of finance (and other aspects) of married life, but then I never had an 'allowance'. We were an equal partnership from the start. Sometimes I earned more, sometimes he did, and his pension is way more than mine for various reasons (most of them surrounding outdated sexist legislation), but we have always been happy to share and share alike.
It is very important that people know how their finances will be impacted by the death of a partner, as well as how they would manage if s/he left the relationship. Being a hostage to fortune is not something I would ever have contemplated.
Sorry if this is stating the obvious, but I was talking to my mother recently, and she had no idea that women no longer inherit their husband's state pension. She is very financially savvy usually, but this change had passed her by, as she and all her friends all have a good income that comes from their husbands' pensions, SERPS and so on, so she had never needed to know. This all changed in 2016, so it may be worth checking if anyone is expecting to do likewise and inherit a spouse's state pension.