Jenny Over-There's nan
In the 925th Universe, Jenny Over-There's nan was one of the untrustworthy people who briefly took an interest in her after her SatNav-based powers became publicly known — which surprised Jenny, as she had vaguely believed her grandmother to be deceased by that point. (PROSE: The Tribulations of Jenny Over-There)
Behind the scenes
The mention of this character in PROSE: The Tribulations of Jenny Over-There is exclusive to the July 12th, 2024 rerelease of the story.
One interpretation is that Jenny's actual grandmother was indeed deceased and the person who tried to speak with her when her powers became famous is a scammer, although it would not be tonally out of keeping for the Jenny Over-There: The Nine-Two-Five Universe series for Jenny's actual grandmother to be an untrustworthy character who faked her death, or somesuch.