The After Party by Anton Disclafani

Two Houston socialites in the 1950's are two sides of a coin. June and CeCe are as different as night and day - June parties till she drops, CeCe stays quiet and watchful and then cleans up the mess. June takes off with men without so much as leaving a forwarding address and CeCe is there to pick up the pieces and wait for June to return. This process begins when they are teens and continues into young adulthood. CeCe's mother dies young and she goes to live at Evergreen, June's family estate. What starts out as a kind gesture gets old when June's family depends on her to know June's every move.
Between June's disappearing acts CeCe will find love, get married and start a family. But every time June reappears her hold on CeCe reappears eventually threatening CeCe's once strong marriage. Both young women are broken and dependent on one another but CeCe's grip on June is too much. Interesting play of what is expected, following society rules, life in a butterfly jar and the cost of freedom.