Lack of male exposure

In my story "How I Became Crossgender" I created a character who was raised in relative isolation by lesbian parents. At age 4 he is put in charge of his 2 year old sister, while his parents build their house. He has virtually no male contact (even via television). There is no indoctrination as to male and female behavior. The children are homeschooled together and are treated identically(with concessions for age).

My story presents one version of the problems re-entering our society at age 13 (11 for his sister) but I wonder what others think what might happen in this scenario.