There are many reasons why women are working outside the home more. As someone up thread already mentioned, many women always worked outside the home. Before industrialization many families earned extra income in various ways based at home: weaving, spinning, brewing, making dairy products, making clothes etc. etc. Rural life was very seasonal, when there was a lull before harvest for example people did other kinds of work; men and women. Don’t forget the enormous amount of people who were servants too.
With industrialization work was moved permanently away from the home/farm/homestead/village. People had to move into cities for work and family life was now on a rigid schedule according to an employers working week. So the idea of a woman being in a home, caring for her children and not being more integrated in the community doing other kinds of work is a relatively recent historic development.
The majority of women love their children, but also in our modern world can feel quite isolated in an American neighborhood of single family homes. The more organic development of homes being close to work, church and community (all within walking distance) kept women integrated and connected to everyone around them.
I think the built environment of the USA with the advent of the car created communities less suited to the human need for community. Being a stay at home parent if you are not in the middle of a city can be isolating and lonely with a lack of adult company. When I had my first child I joined a mothers group at church and we started a program designed by a nun. In the book’s introduction the nun explained when she started working with stay at home parents the first thing she discovered was how isolated and lonely they felt, and so she designed a program to help them build community with other mothers.
In the past, without the physical separation of home and work women could be caring for children while embedded in a community.
There can be a romantic idea of what staying at home full time for years is like. Many people need more involvement in their community in various ways - including paid work outside the home. That doesn’t make them less motherly or feminist, it means they are human and would like human interaction with others over a long day. Noone would think it strange if a man found it hard it be in a suburban house with children all day. They would understand his need to balance his children’s needs with his own needs as an adult. Women are no different.