Mattel's Twiggy doll was the first doll fashioned after a real person (Twiggy was a top British fashion model in the 1960's). She has the same body size as Francie and Casey 11 1/4' and thus could share their wardrobe. She has the same head mold as Casey, but has heavier eye makeup.
She came on the market in late 1967, four outfits were created exclusively for Twiggy and released in 1968.
Her extra eye make-up made her look different from the Casey doll, even though both dolls had the same head mold. Her hair was short blonde, rooted upper eyelashes & painted bottom lower lashes. Bendable body & twist waist.
What's it worth? Take a look at this Twiggy price guide: sold listings for a value indication.