Complex sentence: The Velvelettes continued performing, with various members leaving and rejoining, as family matters dictated, until June 1965 by with time Millie, Norma and Bertha had decided to devote all of their time to raising their families.
Split into simpler sentences: The Velvelettes continued performing, with various members leaving and rejoining, as family matters dictated. By June 1965, Millie, Norma and Bertha had decided to devote all of their time to raising their families.