She's being absolutely ridiculous! Completely pisses me off that a child can't play with whatever they want these days without being labelled as "transgender". 
When me and my sister were kids we loved race cars, He-Man, Thundercats, and actionman. We also loved Barbie, My Little Pony, The Care Bears and She-Ra! We were just kids no one labelled us at all! I hated wearing dresses and skirts, still do so don't wear them. My sister looks like a 50's housewife most of the time, with her big dresses, make-up and love for baking. Same childhood, 2 different people, both still very much female!
My dds, dd1 is almost 16, she's Autistic and very much like a teenage boy, right down to the hygiene.
But she is very much a girl and will tell you she is too. She is into manga and animae, star wars and marvel.
DD2 is 12, she's always played with a mixture of "boys toys" (TMNT, etc) and "girl's toys" (My Little Pony etc). Both hate make-up and dresses and everything a teenage girl is supposed to like, but are still very much girls.
My 3 year old nephew loves Frozen (Elsa in particular), he also loves Ghostbusters, TMNT, Power Rangers and Spiderman.