Yes, and there's a reason for that. The three words -- děvče, dívka, and holka -- for "girl" that the course introduces are not all the same gender. The first is neuter, while the other two are feminine. The gender of am adjective has to match the gender of the noun that it modifies. And it's not actually silly... it's grammar. :-)
I note a lot of discussion here about different words for 'GIRL'. This is not unique to the Czech language. However in a exercise devoted to the neuter gender is is surprising to find that the preferred solution is the feminine form although a valid neuter form is available.