Thumb-Sucking Dolls
Two Thumb-Sucking Dolls - Brother & Sister Cuties
I don't think these were made to be a pair, but they do look cute together. I think they look like brother and sister. Both of them can put their thumb in their little open mouth.
The Little Girl doll is all plastic and is jointed at hips, shoulders and neck. No shoes. Dress looks original and so do the panties. The Little Boy doll is also wearing original clothes. His red shoes are molded on.
The Boy doll has a plastic body and legs with soft vinyl arms and head. He is jointed at neck and shoulders only. Little Girl is almost 6 inches tall and Little Boy is almost 7 inches tall. Features are painted and hair is rooted.
Little Boy doll is marked UD Co Inc, Hong Kong on the body and Little Girl is marked Hong Kong on the body. Both of them are marked Hong Kong on the back of the neck.
Both dolls could use a little TLC but the photo shows they're in good condition for what they are; which is cheap novelty dolls. They are not dated but I would guess they are 1970's or 1980's dolls.