The writers of the Pretty Little Liars show have really done wonders with the character Emily. Emily has grown tremendously and that's something you don't see on a lot of other shows when it comes to character development. The show has coined the phrases 'The New Emily' and 'Badass Emily'.
In the beginning and especially in the flashbacks Emily was shy and not as vocal as she is now. Emily is now bigger, bolder, and badder than ever before. She's making snarky comments about Jenna's walking stick and getting a little wild and sexy in the love and relationship department with Maya. Emily isn't taking crap from anyone any longer not even 'A'. She has challenged 'A' one on one in the greenhouse to show that she isn't the weakest link out of the four liars as 'A' seems to think.
I think we can credit 'A' as well as the short lived relationships that she had with Paige and Samara as the stepping stones and motivations that have given her lessons and inspiration to be who she is now which is 'Badass Emily'.
