Let's discuss why Ashe is the best female character ever...

[maybee]

Yes it was so terrible what Beatrix had to go through. Slaughtering those edefensless rat people was very, very traumatizing for her.

And nobody in FFVIII is an example good anything except Seifer. Selphie is as badly written as everyone else.

Also Tifa helped Barret and them start blowing Shinra stuff up as a way of revenge so she is in no way better than Ashe who also wanted to blow up her enemies.

You're forgetting that Beatrix changed her ways and she realized what she was doing was wrong. She joined Zidane's side and stopped working for Queen Brahne's greed and Kuja's plots.

Selphie was not badly written. She was a cheerful and outgoing character but after the attack on what was her home to her and loosing some of her friends she showed a side to her character that was really brave and mature. She was sad about loosing her friends and people that she knew in Trabia; but she still managed to stand up and still be strong and smile.

Again Tifa realized that doing things for revenge was a bad idea and in Advent Children she tries to be a strong and confident adult and help Cloud break through his depression and be a Mother type to Denzel and Marlene.

Controlling your emotions means what it is controlling your emotions. Ashe going up and slapping somebody is not controlling her emotions, because her sadness and anger leaked out. That is not controlling your emotions.