Having an interesting discussion on academic.edu in response to a question as to changes in the literary depiction of female sexuality following the introduction of the Pill. My initial query was as to whether there were changes.
In response to response, I'm now thinking about
a) the 'vanguard' (as Hera Cook describes them) of women who were leading lives of sexual experimentation or at least eschewing the premarital chastity requirements for 'respectable women' were probably more likely to be represented in novels and short stories of the 50s and early 60s than their actual statistical presence in the population might lead one to anticipate
b) I'm not sure whether the Pill or legalisation of abortion, 1967, was the most significantly liberatory factor. I certainly haven't, so far, found the abortion trope figuring in post-1970 novels except when dealing with the pre-67 past, Whereas I've found quite a lot of literary examples dealing with the pre-67 situation.
c) Or, perchance, increasing destigmatisation of single motherhood, though that might also be related to the above factors.