"I’m so proud of you @kiernanshipka I feel somewhat responsible for you little one," Jones wrote on Instagram of the Chilling Adventures of Sabrina star, who celebrated her 20th birthday Sunday. "You have become such a success in life and in this silly world we call work. I couldn’t have asked for a better on screen daughter/partner in crime. Known you since you were 6! Happy 20th!!! Love Mom." UPDATE: Shipka's Mad Men dad Jon Hamm showed up to her 20th birthday party.