M0nica
I think all these life skills subjects taught in schools, should be gathered together into one subject area called 'Life Skills'.
It can incorporate human biology sex education, which link in with good nutrition and cooking,which link in with budgeting and finance, which link in with saving short term and long, such as saving for a pension, which links in with how banks and mortgages work, which links in with housing options, which links with running a house and having children and basic child care/psychology, which links in with human biology and sex education.
Your idea is fine, but for it to be put into effect you would first need at total revision of how student teachers are taught to teach.
Since the 1970s Danish schools have tried to do what you suggest, but it always fails because to teach a course of the kind you indicate, you would need a maths teacher, a biology teacher and a domestic science teacher sharing the course, either taking lessons in turn, or better still, all three present all the time.
This is not possible due to the way school timetables are written and have to take into account not only how many lessons in each subject children at each level of education receive annually, but how many hours a year their teachers are in the classroom and how many doing other parts of their jobs, such as correcting work, preparing classes, monitering break or invigilating exams.
We were never able to implement a basic grammer course for all pupils doing foreign languages as well as their native language, due to the problems I have mentioned.
And no one teacher is at all likely to be competent to teach all these skills.
The way forward is obviously to include financial training and dealing with taxes in maths, teach cookery in conjunction with a biology teacher and have someone well versed in ethics supplement the biology lessons on human reproduction with teaching of the ethical and moral side of all human relationships.