There is a book entitled "Guide for Catholic Young Women", by Rev. George Deshon, 1910. It is written for single women who are obliged to earn a living for themselves, and how to remain holy doing so. However, near the end he speaks about whether to marry or not, modesty, proper behaviour during courtship, great need of prudence in this matter, especially with a girl who has no parents to guide her, etc. https://archive.org/details/guideforcatholic00deshuoft/page/n287/mode/2up
I know he is not a Church Father, but this seems like a good Catholic resource.