You are correct. Mladá indicates that it is feminine. Masculine would be mladý in this instance.
‘...is he?’ got rejected (2017-09-18). First miss I’ve come across so far in what is pretty much a brand new course. Kudos, Czech team.
I may be wrong but I believe 'is he' is rejected because 'mlada' is feminine, implying you are asking about a female when followed me a non-gender-descriptive term like "je" for he/she. If it was "mlady" then he would be the correct term.
Jak mladá je?
Why "How old is she?" is wrong answer? Not sure that translation has to be literal.
How old is she?
You used the wrong word.
How young is she?
In English these are not the same question either. Maybe how old is she compared to what is her age are the same but how young is she has more to do with the subjectiveness of the answer.
In fast and slow speaker it says "vlada'". Is this a regional dialect use of mlada'?