They have a lot of useful advice on housekeeping, crafts and cooking, and weekly menues in two variants, for those with more or less money. I used some of them as a source of inspiration while planning my own meals. The difference with modern recipes is that ingredients were simple and inexpensive, while the cooking process was often complicated. Nowadays it's vice versa, the recipes usually require fancy ingredients, while cooking methods are very simple.
For instance, in Libelle n.13 which came out on the 29th of March 1940, there is an article about potatoes which discusses several possibilities of preparing them: potatoes stewed with bacon and onions, potato balls in tomato sauce, potato patties with cheese etc. Another article suggests housewives try several ways of making and serving an omelette.
I have a Granny who was like this, she seldom used cooking books but could make several dishes from mashed potatoes or cabbage. Here, for instance is a great way to serve cabbage differently: cabbage burgers. It's my own recipe, which was inspired by my Granny who just turned 90, by the way:
Old ladies'magazines published much more than just recipes, as they contained short stories, romantic novels and information on history and life in different countries. Libelle n. 17 from the same year, for instance, had an article about Dutch princess Wilhelmina and her daughter, who lived in the end of the 18th century.
It's noteworthy, that according to Wilhelmina the happiness in marriage was the result of fulfilling your wifely duties, not of the romantic feelings. She also advised her daughter to flee temptation and not consider herself stronger than others as everybody can fall into sin if he doesn't take care.
Both hers and her daughter's family had constant financial problems so that they had to scrimp and save, for instance, Wilhelmina sent her daughter expensive tea from Holland but recommended mixing it with a cheap brand.
After her daughter's marriage Wilhelmina's other children left, too, and she became an empty-nester, so while her husband was away on business she entertained herself with reading books, doing crafts and painting. When her eldest son was planning to marry, it was Wilhelmina's task to see to the renovation of his future residence according to the modern standards.
The article (written by Dr Mrs Klijnhout) doesn't say that Wilhelmina was engaged in state business or in political intrigues, she seemed to be quite content being the wife and mother and doing usual feminine stuff, first raising children, then marrying them off and engaging in hobbies and crafts, and trying to practise economy yet she seemed content though she lived in the times of social upheaval. I think she is a good example to the modern women.