I have a dim memory of Shiera taking over Kendra's body after Kendra committed suicide. Or was it the other way 'round? And what happened afterwards?
I wish DC had established from the start of the Silver Age that the Thanagarian Hawks were completely different persons from the Golden Age pair, as they did for the Green Lanterns and the Flashes. IMHO it was a mistake to give Katar and Shayera names that were too similar to Carter and Shiera to make them different people, but not similar enough to make them the same. Too late now for a name change, but please at least stop trying to conflate them.