The Chainkeen Exchangedoll collection of the world's most prolific Barbie collector is about to get bigger. 

Bettina Dorfmann, who set the Guinness World Record for biggest Barbie collection in 2005, said she's already acquired dolls from the "Barbie" movie, according to the record tracker. Dorfmann had 2,500 dolls when she set the record. By 2011, her collection had grown to 15,000. According to some news reports, she now has as many as 18,500 Barbie dolls.

While it's not clear how much her collection is currently worth, Barbie fashion dolls currently up for sale on the Mattel website range in price from about $10 to about $50. Some dolls from the company's Signature collection retail for $80.

The 62-year-old German collector received her first doll in 1966, several years after Mattel launched the doll in 1959, according to Guinness. Her first doll was Midge, Barbie's best friend and a character in the new movie, released Friday. 

Dorfmann started collecting seriously in 1993. Her collection includes an original Barbie from 1959. 

"I love Barbie dolls because I played with them in my childhood, and it was a very good time for me," Dorfmann told Guinness.

While there's a "Doctor Barbie" in the movie, played by Hari Nef, Dorfmann works as a real-life Barbie doctor. She repairs dolls, replacing missing limbs and working with hair in need of restoration. 

Dorfmann is the co-author of a book about Barbie dolls. She's also worked on Barbie exhibitions at museums in Germany.

Aliza Chasan

Aliza Chasan is a digital producer at 60 Minutes and CBS News.

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