Is it correct to say that granddaughter is grandma's intimate little cotton-padded jacket?

Granddaughter is grandma's little cotton-padded jacket, yes. Small cotton-padded jacket is a metaphor, which is a high summary of the intimate relationship between relatives. Generally speaking, a child who is filial and considerate to his relatives is called a small cotton-padded jacket. The image interpretation of children's care, care, understanding and help to their loved ones and emotional integration is often called intimate little cotton-padded jacket because of the delicate mind and affectionate tenderness of girls.