As Lorca was writing Blood Wedding, Spain was undergoing many social changes that inform the play's treatment of feminism. At the time of the 1928 murder in Níjar on which the play is based, Spanish women lacked many civil rights: They could not vote, get a divorce, or seek an abortion. Furthermore, adultery was a crime and women were not guaranteed the right to hold a job. These restrictions heavily influence the Bride's worldview; marriage was indeed a binding and in some ways repressive life choice, to an extent that contemporary women can only imagine--but it was the only one available since women could not be sure that they would be able to support themselves.
With the rise of the left-wing Spanish Republic in 1930, women began to see improvements in their status. Abortion and adultery were no longer crimes, and Spanish women received all of the civil rights of their counterparts in America and the rest of Europe. These changes would have been on Lorca's mind as he was working on Blood Wedding, which was first produced in 1932--indeed, the events of the play are somewhat inconceivable in a society where women have equal rights. However, attitudes were slower to change, especially in rural societies, and the fact that divorce was legal did not mean that it was condoned.
In any case, the flowering of democracy that Lorca witnessed was short-lived. With the ascendancy of Francisco Franco in 1939, after a long and bloody civil war, many of the newly-granted women's rights were revoked, and the Catholic-influenced state encouraged women to be homemakers. It was only in 1975 that women were re-granted the rights outlined in the 1931 constitution.