She is first mentioned in "The Amulet of Avalor" by Roland when he tells Sofia the reason he gave her the Amulet of Avalor after it was stolen by Jasper. She told him stories about the Amulet when he was a boy like how it would guide and watch over its wearer.
She makes her debut in "Best in Air Show". She first appears after she arrives at Enchancia Castle. She reveals that Count Barnstorm and the Flying Starwings are coming which she's looking forward to, to Roland's shock. Later, she tries to sneak into the Royal Stables but gets caught by Amber and James. After trying to cover herself with claims of ignorance that the twins easily see through, she tells Amber and James she wants to enter the Starwing Amateur Stunt Flyer contest due to wanting to be a stunt flyer ever since she was a little girl. She also tells them that she needs a horse and disguise so Roland doesn't find out and the twins agree to help. During the contest, disaster strikes when a hoop falls on her horse but she gets saved by Sofia's horse Minimus in a way that makes her disguise come off. Grand Mum tries to tiptoe away but is caught by her son. Roland asks his mother why she didn't tell him the truth and she tells her son she felt he couldn't handle it. She then takes part in the Starwings' grand finale along with her youngest granddaughter.
She makes her second appearance in, "A Royal Wedding" where she informs her son that Amber is the heir, not James because the firstborn gets the throne. She showed the family the law and explained that Tilly had willingly abdicate her role as heir to her brother because they both knew he would be a great king, because it was his dream. Later, she is seen crying tears of joy at her daughter's wedding.
Her last apperance is in the series finale, "Forever Royal". She does not speak throughout the episode, though her facial expressions tell others how she's feeling. Both she and Tilly were proud of Sofia's desire to protect the kingdom and encouraged Roland to return to the castle to fight Vor.
Her voice actress, the late Florence Henderson, is most famous for her role as Carol Brady in The Brady Bunch.
Technically speaking, as former queen, she should be addressed as Dowager Queen, not Grand.
Much like her daughter, she is more adventurous and knowledgeable about subjects that her son is naive about.
She and Tilly also share the same facial structure and hair color in the past, though Tilly got her eye color from her father, Roland I.