That's one way to go about it. Alternatively, you could come up with three clear differences between the two. Then, you could write an introduction in which you summarize the similarities, but end with a thesis that states that the differences are greater. Then, you could dedicate a paragraph to each point, comparing the differences between raising a boy and raising a girl as they relate to that point within each paragraph. So,
Para 2
. . . . . diff 1
. . . . . . . . point A (boy)
. . . . . . . . point A (girl)
. . . . . . . . point B (boy)
. . . . . . . . point B (girl)
And so on for the others. This will tend to give you a more focused essay than having two or three paragraphs that you can't really tie back to your thesis.
Sean, EssayForum.com