The issue here is contract law.
Women can now own property just like a man. Any joint property would be split up just like business partners dividing a business.
Basically everyone would want a prenuptial agreement. That would be neither expensive or difficult to do. There might even be some basic laws regulating it.
The state should butt out of religious institutions and marriage is essentially a religious institution.
Going the other way I think that if a state is going to sanction marriage then it should spell out common law marriage. People that live together for “X” number of days or who have children together whether they live in the same household or not should be considered married for tax, inheritance and child support purposes. I find the statement of people who have three kids but say “Oh we’ve just been living together for 15 years, not ready to tie the knot” to be laughable.
How do we make the parent who abandons the children pay for their upbringing (instead of us taxpayers)?