Well she does live in Japan and there's a lot of social pressure for women them to get married and become a mother. I'm honestly surprised you find the author has patriarchal values because I think her work is pretty unique and progressive compared to other manga. She wrote that Tokyo Tarareba Girls is based on some her unmarried friends around her age who at the time and actually admires single metropolitan working women (the references to sex in the city makes me think that th is story is also inspired by that too). I think that even though the main characters want to get married the author has different views since none of her stories actually ends with the MC getting married and is more of a commentary on how Japan's society's expectations of effect them.
She started writing a manga about men training to be house husband's and was met with heavy backlash and had to cancel it.
I actually wanted to comment the same thing. I love this author's depiction of women and femininity in Japan!
This author really likes to act like women are completely defined by their marriage status. All of their josei stories are like this x is x age and unmarried... bam prince charming turns up. Such a shame thought this would be a cute, modern drama but it's still stuck with archaic patriarchal values.