Madonna's 12-year-old twin daughters Stella and Estere proved they're growing up so fast while posing for a photo with Billie Eilish after attending her Oct. 17 concert in New York City.

Billie Eilish has swept the country recently with her highly-anticipated Hit Me Hard and Soft Tour, leaving fans in awe of the Grammy winner and her blockbuster show. Billie is known for her ...