Not much is known about Lysette's past, other than that her husband Ira and son Charlie are both now deceased. It is hinted during Conway's visit to The Lower Depths that Lysette and Conway have a failed romantic history - the song "Too Late To Love You" was likely originally performed by Lysette, about Conway. Another piece of information obtained from The Lower Depths was that Charlie's death, by falling off a roof he was working on, was due in part to Conway being too hungover to go to work that day, causing Ira to have Charlie go in his place.
During Conway's drug-induced dream at Dr. Truman's house, he sits with Lysette at breakfast. They discuss her son Charlie's death falling off of a roof, and her departure with a woman named Cora. During act IV, Conway tells Shannon that Lysette is going to live with her sister.