We are long past the idea that not marrying is not gender conforming.

Also, historically in countries like the US, there was always a small but significant number of women who never married. For example, in the US from 1890-1940, the percentage of women over age 35 who had never married remained pretty steady at 8-10%. The % started dropping in the late 1940s through the 1970s.

The time when the proportion of women 35+ who had never married in the US was lowest was 1980.

In all of the 20th century, the time when the proportion of women over who 35 had never married was highest was in 1920. Only in 2010 did the proportion of never married women over 35 reach the same level - 10% - as it had been in 1920.

https://www.census.gov/content/dam/Census/library/working-papers/2012/demo/sehsd-wp2012-12_presentation.pdf

In the baby boom era & cultural milieu (Roman Catholic) I grew up in, it wasn't at all uncommon for women to choose never to marry. Lots of Catholic girls & women became nuns (my own father had his heart broken in 1939 when his HS GF informed him she was dumping him to enter a convent). Other women lived as "spinsters" or with women in "Boston marriages." In my own family, there were a number of women on both sides in the 19th & 20th centuries who never married. Some entered religious orders, but most were "maiden aunts."

When I was growing up in the 50s & 60s, my parents also counted a number of never-married women (& men) in their social circle & I had "lay" teachers who never married. Nobody thought anything of it. Some people back then were simply said to be "not the marrying kind." Sometimes this was code for gay or lesbian, but it also communicated to me & other kids that marriage isn't for everyone - & that's perfectly fine & "normal."