Beatrixo (Jayne Eastwood) is Betty's grandmother, a lively older woman with a love of clog dancing and numerous other talents. She lives on her farm in the countryside just outside of Moose Jaw Heights. However, she is not only a retired Galactic Guardian, but was also one of the first Galactic Guardians, and, in her younger years, looked like an adult version of Betty. She only comes out of retirement occasionally if Betty is in serious need of help.
Despite being retired, most of her old equipment remains functional; her starcruiser, the Century Warbler, remains operational. Betty had discovered her own grandmother's past when she discovers her old Galactic Guardian bracelet (similar in appearance to Betty's own) in her attic, but she at first shrugs it off as merely being coincidence. She didn't believe it at first until in "Evil Idol", she presents Betty with a special locket for her birthday, to be used whenever she encountered trouble; when Maximus later captures her on a Galactic Guardian mission later that day, Betty discovers her grandmother's past when the locket is revealed to be a signal beacon; Beatrixo manages to save Betty and her crew. Betty realizes all of it is true.
Despite her advanced age, Bea still possesses incredible fighting skills and can hold her own with many opponents.
Beatrixo has a sister, Auntie Matter who she has a bitter sibling rivalry with. Auntie Matter is also one of Beatrixo old archenemies from her youth mainly due to her sister's power to turn herself into a black hole which according to her she inherited from their father (indicating that it is possible that Betty's great-grandfather wasn't human). Beatrixo, however, is said to take after their mother (who was likely a normal human like Beatrixo, Betty's Mother, and Betty herself) who possessed no super powers. At one time or another, Beatrixo and Auntie Matter have been romantic rivals (fighting over various boyfriends), which includes Jimmy, Beatrixo's husband.
She never tells her daughter, Betty's Mother, who she really is. This cause to have their difference. Nor why she never tells her daughter who she really is, fans think that she wants her daughter to have a normal life and want to protect her. Similar to Betty's way of keeping a secret.
There are rumors that Beatrixo might be the one that recommend Betty to the Galactic Guardians and this caused the Galactic Guardians to recruit Betty.
- Despite normally being shown as being Betty's maternal grandmother, in the episode Trouble with Triplets she was shown as being her father's mother.
- This is likely not the case, though Betty's Dad referred to Beatrixo as his mother, this could be like some adults that treat the parents of their spouse as their own parents, normally when their own parents are deceased.