Firstly, in order to know the seed phrase, the other half must understand how to use it. Just like that, a set of words will mean little to a person far from bitcoin. But if we talk about the family, then in a normal family there should be some kind of common budget, and each of the spouses can have personal money, provided that both partners work. But if necessary, all personal money, of course, turns into a common one..
I know that in Eastern families, money is always controlled by a man, and women have to constantly depend on him. In my opinion, this is not entirely fair, although, of course, I will not judge the customs of other countries.