Dinah Laurel Lance, daughter of Dinah and Larry Lance, was kept within a sleeping envelope energy cocoon until her mother's memories were transplanted in her mind, allowing her to control her powers and move to Earth-One to begin a new life after nearly a quarter of a century in slumber. Kara Zor-L of Earth-Two lived for over sixty-five years including a lengthy period in suspended animation. For the period that Dinah, aka the second Black Canary, lived away from Earth-One correlated with Kara aka Power Girl's journey. Meanwhile, the Kara of Earth-One... Supergirl... had a much shorter life span which was compensated by Lance's counterpart on that world, Silver Swan, who lived continuously on Earth-One for her entire life.
Then there was the presence of six minature clones of Supergirl. Created by the evil Council, they were defeated by the Girl of Steel and left in suspended animation after being stripped of their powers by gold Kryptonite. Just like Power Girl had been, thought not nearly as long! Eventually, the six former foes of the Maiden of Might reassembled into a full sized version of their template and assumed the identity of Linda Danvers. This replica of Kara Zor-El continued to remain alive after the original Supergirl perished during the Crisis on Infinite Earths, wherein Kar Zor-L continued to life and operate as a superheroine now without par.
Other clones were the Bizarro Supergirl and another variation of Zor-El created in Supergirl v1 #10, a male known as Superlad. Sent on a mission to steal riches for his designer, he took his life soon after he had been spawned rather than kill his "sister". Similarly, the Bizarro Maiden of Might wasn't long for this world.