Phil, thank you for the correction about the CC’s second rebbetzin. She was married previously but she was young when marrying the much older Chofetz Chaim. In fact she survived WWII and lived in America after the war and her kever is in Queens.
Regarding the Ribnitzer Rebbe, I believe his second rebbetzin, who was far younger than him, was never married before marrying the Ribnitzer nor after he was niftar.