she had said that to me after i came home from work one day ans was complaining aout something that had happened... . she immediately shut me down with that comment and i felt deregulated... . like my feelings and emotions didnt matter
you must remember you are dealing with someone who mirrors the "good" and "bad" you cast out in order for her to create a sense of "self". an inner identity.
when you come home in a negative state and start complaining, you are representing the "bad" in her (from mirroring) that she desperately tries to avoid. she doesn't care that you had a bad day or how you're really feeling. she is concerned that you are bringing out the "bad" side in herself that she replicated from your behaviour.
because she doesn't have a sense of who she is or how to be in the world, she uses your behaviours as a guide to design a false sense of reality.
when you display "bad"(complaining), she mirrors that and interprets it as her being "bad". she then feels anxious and must blame someone else for the unexpected feeling of "bad" that she now feels.
"stop being such a girl about things" is a projected feeling of anxiety towards herself to stop the "bad" feeling residing internally.
if she can stop your negative behaviour from continuing, she will decrease the "bad" feeling she is mirroring from you.