Would it be wrong to teach children about heterosexual love and romance?
If, by teaching children about heterosexual love and romance, you mean placing an age-appropriate book in the hands of a child that will interest that child and get that child to read, then, no that is not wrong. For children who enjoy reading, there are plenty of books to be found in school libraries about heterosexual love and romance. Here's a link to a brief list of some of these:
If your tween wants romances, hand them one of these cute middle grade romance books -- some about crushes and others featuring tween first kisses.
readingmiddlegrade.com
Admittedly, I was the kind of kid who would more readily pick up a horror novel by Shirley Jackson than read about Laura Ingalls' budding romance with Almanzo Wilder in the
Little House on the Prairie books. But the point is that
there are young people who want books that portray their own situations and experiences. Until very recently, there really haven't been any books for children attracted to the same gender as theirs. These children exist, whether or not people are comfortable acknowledging this.
I agree that books containing sexually explicit scenes are inappropriate for young children and, from the reviews I've read about the sexually explicit scenes in the book
Gender Queer, I do not think it's appropriate for a school librarian to blithely hand that book over to a child without some parental permission. Especially since the publisher's recommended reading age for
Gender Queer is 18 years and up (see product details on the book's Amazon page).
There are now being published numerous age-appropriate books that address homosexual crushes between young people. However, it seems to me that the anti-LGBT battle has been taken to
every book that contains a homosexual crush of some kind. That, to me, is a problem.