Hanako

She is Ash's mother. Delia is very caring of her son, always reminding him to do his best. She is very talented, having won a beauty pageant and cooked a dish so popular that elite chefs at the Indigo Plateau have asked for its recipe. It is not known who is the father of Ash, but it isn't clear that Ash's parents have separated, although she has contacted him at least once since Ash left. She has a Mr. Mime housekeeper who helps her with chores and is also rather adept in battle. In the Japanese version, the name of Satoshi's mother was, for a long time, unrevealed (with her referring to herself as Satoshi no haha or referred as Mama-san, although the role was credited as Hanako).

The name Hanako (and its English counterpart, Delia) was revealed during the second Pocket Monsters movie. She also is constantly reminding Ash to change his underwear. (Source: Wikipedia)