If you say discard right away, it's like saying discard own parents. It's easier said than done.

you feel disappointed because you still have that idealistic dream of having a good girl

maybe yourself don't have many girl experiences before, but people come and go by themselves. Have a realistic goal with your unnecessary expectations. You likely already picture having how many kids with this person without even recognizing own problems as well

she feels defensive because you (yourself) are defensive as well, you may not be a good role model for her, so does her own parents. There's nothing much you can do when it comes to "changing" her, but time will tell whether she's completely loyal to you.

when it comes to advice, people project their subjective experiences. There's no absolute right or wrong black or white. Therefore when people ask for advices, they usually ask for listening ears.

If you give good advice, they may not mention your name
If you give bad advice, they may even blame or hate you

either way there's no good outcome from it

There's so much you can do ie anger management
If she believed you're good for her, she would change herself without even you asking for it.

If you still have doubt, just break it off
otherwise be single and at peace yourself

I mean nobody is perfect
TS has own emotional baggages, it will be unfair to question this girl motives while ignoring his cause it will be a narrow perspective