My gf changed all of my pwords..is it normal??..do u girls do this?

my gf of 5 mons came that noon to my place and asked for my email ids..i told her..then she askedme for my pwords..and i reluctantly gave them to her after she emotionally blackmailed me. then she proceedded to change all of the pwords to her name..so if her name is trish .the new pword is 'trish00'..and after that she kissed me and left as if nothing happened. i called my frnd and told him about this..expecting him to say its worng..instead he told me that it took his gf 3 mons to change his pwords. he said all the girls do this. and im kinda freakin out here. all the girls do it??..now she is not a bad person..she is the most perfect person i can ever find..she is wifey material as they say..this is my first serious relationship and i hav been shy about girls.. so i dunno..do u all girls do this?..is it normal??