I loved her 'don't you remember that we're AWESOME?' message to Lee and apparently it's just what he needed to hear because after that he completely levelled up.

Well put! That is pretty much exactly how I read the scene too. The adrenaline and exhilaration of finding herself and them as duo in a situation where they MAKE SENSE and kick ass. For someone who has been lost inside of her own identity dilemma for a while, this much have been an amazing relief: I know how to do this. I know how to fight. And Lee is my partner.