That didn't sound like niña at all to me! Maybe it's because I'm a native speaker -- though it is important to note that 'niña' and 'línea' don't 'rhyme' in Spanish. That is, if I spelled 'línea' and 'liña' it would be pronounced differently.
In Spanish there is a separate, individual sound that to a lot of English speakers sounds like n + y. Most English-speaking Spanish learners would say n+y = ñ, but actually, ñ is a different sound from the two. Spanish and English both have the 'n' and the 'y' sound (for the spanish speakers who don't believe me, think words like 'hielo') but Spanish has an extra sound that English doesn't: the ñ.
It's hard to explain how it's pronounced exactly, and how it differs from the normal n (and it's especially hard over the internet lol) but http://en.wikipedia.org/wiki/Spanish_phonology is a good place to start.
TL;DR línea = linya niña =/= ninya
In English you put multiple adjectives in a specific order https://image.slidesharecdn.com/hot-action-adjective-order-part-4-1196096415290537-2/95/hot-action-adjective-order-part-4-1-728.jpg?cb=1196067616
That list is an opinion, not a rule. There is no rule that I am aware of for adjective order in the English language. There are multiple lists, each differing from the other, as they are each based on a different opinion of what order adjectives should appear.
Gingersoftware, The Cambridge Dictionary, and LearnEnglish (from the British Council) each have their own lists, each with a different number and order of categories