Since Bitcoin is all about privacy it will be wrong to give out your seed phrase to your family or even your spouse especially when you are holding and chasing a particular target but i feel if the person, that's your wife or child is already exposed to the technology then it will make the whole scene different because it will be easier to actually set some up some way for them to actually inherit your holding when you are no more .
We no that the privacy of our phrases is very important but however deciding not to show it to our wife is not ideal because so far life is concern nothing is certain anything can happen to someone, and what if perhaps something happen to the person how would the family get hold of the account.
So we can keep our private phrase from our family members but not to our wife but however you can plan it in a way you can only show her the place where you store it but will not allow her to get access to it yet, so with this way your phrases will be well stored and perhaps if something happen your wife will be able to make use of it.