She worries a lot about her son and "mothers" him. She thinks very highly of him and would like to introduce him to Bean, telling her Bean that she looks like she is in his league. Her over-bearing and nagging character undermines Mertz's masculinity and bravery as a Knight.
She tagged along on the Quest for the Eternity Pendant in S01E08 and was a source of much annoyance. After Bean and Sorcerio get pulled over the Edge of the World by mistake, Luci decided to jump off with them rather than risk having Mrs Mertz say something to him. By the time Big Jo and Porky ambushed the Knights she was tied up - along with Pendergast, Turbish, and Mertz - and gagged so she wouldn't speak.
She makes a cameo appearance in S01E09 after the battle of Elfwood, after Elfo was tragically shot with an arrow
Mrs. Mertz appears as a round, shorter woman wearing knight's armor, with two locks of brown hair sticking out from the top of the helmet's visor, and pinkish-gray slippers. The helmet has a reddish-brown plume on it, and appears age-worn