Nobita's grandmother is the mother of Nobisuke and Nobirou Nobi, and also Tamako Nobi's mother-in-law. She was gentle and affectionate to Nobita, but she passed away when Nobita was still in kindergarten. She gave him the motivation to conduct himself like a Daruma doll (being able to stand up again and again, despite failures after failures). Nobita still keeps the Daruma doll, and sometimes talks about it to Doraemon.

(Source: Doraemon Wiki)