I don’t know but educators are supposed to understand how children think. Specifically, at the elementary level, boys thinks girls have cooties, or whatever term is hip today. To introduce them to the gay concept is off their radar at this age. But they do understand an adopted kid.
I really think rather that get bogged down in the gay issue, the text and lesson should focus on adoption of a child. Period. Teach these kids that an adopted child is the same as every other kid in school. Big lesson here.
Now as the kids mature, you can introduce gay parents, non-traditional lifestyles etc. Fine. Early elem education including two mom adopting a kid complicates the issue and to me points to an agenda.
I could be argued that captitalists are exploiting the liberal educators and playing into their hand and creating new textbooks for sale at taxpayers expense.