'वह बड़ी गया है' would be 'That is a big cow'. Just like in English, attributive adjectives appear before the noun they are describing. So, in this sentence 'बड़ी गया' /'big cow' would be a single noun phrase.
I just love how the DL exercises of the different courses reflect the culture related to the languages. Here, one of the first animals we learn to say in Hindi is cow. Not the case in the other courses I take.