Grandma Lane
Grandma Lane (just called "Grandma" in the episode) was one of Jane's grandmothers in "The Teachings of Don Jake", who had travelled to the annual Lane family reunion in the Midwest.
She has a wheelchair and seems quite feeble with a low voice... until, once she's gotten "Janey" to "come closer" so she can be heard, she screams "What the HELL is WRONG with you!!!" in a loud voice. We don't know what it is about Jane that enrages her so.