Its idea of “wholesome things” that should occupy a girl’s life don’t include cooking, cleaning, or obeying men, so it might be a bit more modern than the 50’s. The fact that it doesn’t seem completely freaked out by the thought of girls masturbating (and even admits it’s very common) suggests the 70’s or early 80’s.

And if it were a Christian schoolbook it’d be demanding an exorcism for any girl that even thinks of touching herself, so it’s probably just a bad psychology book or a self-help book on parenting from the 80’s.