Boys will be boys. And girls will definitely be girls. In Rebecca, both men and women are shown as constrained by the gender roles of their society. Women seem to have a severely limited number of acceptable activities and employment opportunities. Educational opportunities aren't even mentioned. This isn't even to mention the pressure on married women to produce a male heir. But wait a minute, Daphne du Maurier does not neglect the male perspective. Maxim de Winter, the male lead, is shown as absolutely tortured by what he sees as the need to project a façade of perfect husband. This theme of gender is fairly subtle in Rebecca and wide open for lots of interpretation, especially since literary critics are just beginning to see this novel as a classic. (Oh, and one last thing: there are lots of comments about female characters who should have been boys, or who were like boys, or who feel like boys. So watch out for those moments when you read.)
Rebecca's extreme femininity threatens Mrs. de Winter, who isn't sure what her role as a woman should be.
Forget about women's issues: Maxim is under extreme pressure to conform to the norms for males in his social and economic class.