Anat Hoffman, who was among those detained, said the women were stopped because they were wearing religious garb that Orthodox Judaism reserves for men only. The incident occurred at the Western Wall, one of Judaism's holiest sites.
Silverman's sister Susan, a Jerusalem rabbi from the liberal Reform stream of Judaism, was detained along with her teenage daughter.
Sarah Silverman wrote on her Facebook page that she was "SO proud" of her sister and niece for their "civil disobedience." The original post included more explicit language typical of Silverman's humor.
The women belong to Women of the Wall, a liberal group that goes to the Western Wall each month to worship. They conduct certain rituals, such as wearing prayer shawls and skullcaps and singing out loud, practices reserved for men under strict Orthodox interpretations of Judaism. Hoffman, who was among those detained, is chairwoman of the group.
Police spokesman Micky Rosenfeld said the women were detained because they acted against court-ordered regulations that bar women from wearing prayer shawls at the Western Wall so as not to offend Orthodox Jewish worshippers. Rosenfeld said the women were released after several hours.
The group has been gathering at the Western Wall for a quarter century, but in recent years its activists have been increasingly detained by police. Hoffman, who chairs the group, said no woman detained has ever been formally charged with any crime.
"This is just attrition," said Hoffman. "They want the group to become frightened."
The Monday detentions took place after about 300 people gathered at a prayer service at the Western Wall to protest Orthodox control of the site.
Among the worshippers in the group, Hoffman said, were about 100 male supporters, including veterans from the legendary Israeli paratroopers' battalion that captured Jerusalem's ancient walled Old City, including the Western Wall, in the 1967 Six-Day War.
In December, after Hoffman was arrested under similar circumstances, Prime Minister Benjamin Netanyahu ordered the head of the semi-governmental Jewish Agency to come up with solutions that would allow for non-Orthodox women to pray freely at the site.
Hoffman said two of the women held by police were American rabbis from the egalitarian Conservative Jewish movement who missed a scheduled meeting with the Jewish Agency chief to discuss the very issue that landed them in police custody.