It is called the Tom boy phase. Plenty of girls have that.
I know I did. My sisters did not. both the have degrees in Accounting and Finance and I went in the Army. But I never once wanted to be a guy. I am not girly, which God understood and blessed me with only sons. These days it is crazy that society thinks that kids know what they are.
I was a tomboy, I had 4 older brothers I could hardly be anything else.
I was a tomboy, too. One older brother who got to do things that were so much more fun than I was allowed.....mostly playing baseball. Even though the Good Lord only blessed me with one child, I am eternally grateful that my child is a boy. Oh, the fun I had with him while he was growing up! Now I have a granddaughter and she is so much fun, in a different way. Tomboys rule! And I bet she will be one : )