It's a weird take.
I don't think her unhappiness has anything to do with feminism.
There are women with high powered careers who are single, married, cohabiting, with or without children. Some of them are happy, some of them are unhappy. There are also women who don't work outside the home and are financially dependent on a man. Some of them are happy, some of them are unhappy.
Feminism will not make you happy. Having a high powered career will not make you happy. Having a husband and children will not make you happy. If happiness if your goal in life then none of these things in isolation will get you there.
Where I think feminism can help women to be happy is that, by encouraging women to be financially independent, it gives us options. We can take control of our own lives and don't have to be like the Bennet sisters, being paraded in front of every eligible bachelor in town to make sure we don't end up being penniless spinsters. We can choose not to marry. We can choose not to have children. Most importantly, we can choose to leave an unhappy relationship.
I think for women who are past childbearing age who would have liked to marry and have children but didn't, the grass is always greener on the other side. I don't for a single moment want to diminish the sadness of a woman who will never experience motherhood when she would have liked to, but it is absolutely not the case that all or even most women who settled down and had children and did a little part-time job are happy and fulfilled in their lives. Many are not.
At the end of the day all we can do is make whatever we feel are the best choices at the time, and try not to end up, in our later years, regretting those choices and wishing we had made different ones.