Hanako

Hanako (Delia) is Satoshi's mother. Hanako 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 Satoshi's father is, and it is unclear as to whether he and Hanako have separated. She has a Barrierd 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 in the English dubbed version.

(Source: Wikipedia, edited)