Is my girlfriend still attached to her ex?

My girlfriend treats me disrespectfully and when I ask her friends about how she treated her ex they say that she was never like that and they found it weird that she does this to me even though I treat her nicely.. she mentions her ex and compares him to me every time we fight (btw she has been picking fights all the time) (We've been together for 2 months).. when I say "he treated you like sh*t he even cheated on you, and you still mention him do you still love him" she says no but then she even defends him.. I'm starting to have doubts about if her love for me.. should I leave her? or should I try to put her feelings back together and if so.. how can I get her to be re-attracted to me?
Is my girlfriend still attached to her ex?
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