Why do you break the lore of mass effect universe?

And about Darla vas Hyperion and the question why a human would acquire Quarian habits and customs ...

You could also ask these questions:

• Why would the British ambassador to Saudi Arabia, a jew, convert to Islam? Google him: Simon Collis
  
  
• Why would the Italian ambassador to Saudi Arabia, a Catholic christian, convert to Islam? Google him: Torquato Cardilli
  
  
• Why do surprisingly many of the Syrian refugees, all Muslims, who found shelter in Western countries all of a sudden convert to Christianity? There are many stories like this one: (article)
  
  

The answer is simple: We humans are easily influenced (and impressed?) by other potentially 'exotic' cultures, especially when we (have to?) live in it day in day out.

So when the real-life ambassadors of the UK and Italy in Saudi Arabia convert to Islam e.g. because they are exposed to that culture every day (and were fascinated?), and when real-life Muslim refugees convert to Christianity because they found shelter in Western countries and they find Western freedom of religion and Christian ideals way more appealing than those Islamic societies they left behind...

Is it really hard to imagine that a human living amongst Quarians would sooner or later develop Quarian habits and an appreciation for that culture? Nope, not at all.

;-)