I arrived in front of the café and perceived saw Helen inside, I entered/came in.
"Hi Helen, are you ok ? I was worried about your famous this announcement you talked so much about... (j'imagine que tu voulais traduire le mot "fameux"? Si tu utilises "famous", cela voudrait plutôt dire "célèbre") What's happened ?" I said to/ I told her her hastily.
"Don't panic Mathilde, it's nothing grave serious," she reassured me. "Well... I need you to be understanding, and I know it's not easy," she added anxiously.
I answered her friendly I listened to her I told her gently that I would listen to her.
"So ... I've decided to give up school/studying. It can be surprising but I've been thinking about it for a long time andso my decision is final made," sShe kept an extremely serious face/her face remained serious, I was amazed, yet I wanted to know whaty this sudden change was aboutthat I didn't understand. So I declared/said (les repetitions de (say) ne sont pas génantes en anglais, c'est même plus idiomatique), as ifpretending to be surprised "Why ?!"
"I'm tired of/bored with the school, I want do to have/live new experiences, to confront the working life ! You see what I mean ?" She told to me cheerfully with a big grin/in a big smile.
"Helen, it's not so/that easy, you know. To work, you need degrees and you have no experience. You should take your time and wait a few years," I advised to her.
"Experience grows is acquired through working", she retorted a little annoyed, "and the school doesn't suit me any more, I want to leave/give up."
"Would you like to change sector subjects/your options or to study ingo to another school ? You could do what somethingdo you prefer," I tried again.
"No, what I want it's is to work, nobody can change my mindopinion. I would prefer you to (be from my part on my side and to) support me."

Je me suis juste permis de rajouter deux ou trois commentaires. J'espère que ça ira!

Bonne année à vous!