It's a bit funny, we understand easily sentences like 'I am a whale', or 'this deer doesn't speak english', but when it's about girls being boys, we try to find some big meaning, progressive thinking about gender stereotypes and what not :) sometimes a cigar is just a cigar, and a weird duolingo sentence is just a weird duolingo sentence :)
"Jeg er en hval" could be helpful if you were a whale trying to describe yourself. "The deer doesn't speak English" could be helpful if you were trying to get someone to stop yelling at a deer. "Pigen er en rigtig dreng" could be helpful if... Maybe, what you thought was a girl is really a boy? Or maybe they identify as a boy? Or maybe they were once a girl but now not? Or maybe you are questioning the validity of their proposed gender? You see, this sentence is just really ambiguous. In English, you would say "they identify as" or "he's/she's transgender/nonbinary/etc." etc. So, I think it's just unclear what exactly is meant by the sentence.
Maybe the sentence is about gender stereotyping of children.
I found a Danish language article: En "rigtig dreng" kan også være en pige (= A real boy may also be a girl)
The google translate version of the abstract of the article says, in part:
- There are strict limits to how boys can be boys, and girls can be girls in the Danish kindergartens. Children who are a little out of the norm, is likely to feel outside the community. The study shows "More than two kinds of children" ...
My lovely Danish girlfriend whom I hope to one day marry (we've dated a month over a year and a half now) was utterly baffled by this sentence. She guessed it was a reference to Pinocchio, but she didn't seem very certain.
In response to that website, my gf certainly never received any assistance in school for HER gender identity issues in the schools, and she was even assaulted and harassed by teachers for not adhering to proper gender roles. This was in public school by the way -- NOT in a Christian school!
That said, her mother is a kindergarten teacher, and apparently, the procedure of making note of gender non-conforming individuals has only very recently been put into practice. If only such things were practised in the schools when we were young... :(
"Right" in this sense means "absolute, total". She's a right boy = She behaves just like a boy. It's used to convey emphasis (and frequently in an uncomplimentary way!) Other examples: "I felt a right idiot" (Me sentí un idiota completo). "Their house was a right mess" (Su casa era un lío total).
Kudos for Duolingo to include transgender equality as part of its linguistics, especially considering Denmark was the first country in the world to have legally recognition of same sex relationships and has some of the, if not the, most progressive attitude to sexual and gender minorities. Well done I say!