Delia Ketchum is the mother of Ash Ketchum and mother-in-law of Misty and ex-wife of Giovanni, because of all the torture and abuse that he has done to their son, which resulted for a divorce that she realized that Giovanni was nothing more than just a sick savage, and she also used to run a restaurant and she is also a descendant of Sir Aaron.
And she is reprised by Veronica Taylor (Who coincidentally voiced her son) in the English dub and Masami Toyoshima in the Japanese dub.