scared, worried or afraid for her

Which of these is said in everyday English naturally? How to say the rest?

My sister is in a bad relationship and I am scared for her.

My sister is in a bad relationship and I am afraid for her.

She is in a bad relationship and I am worried for her.

I don't know how to put this? Can you be stressed for someone?

She's the one who should be stressed since she's the one taking the exam, yet I'm stressed for her.

I was stressed for you as if it was me giving the interview.

Looking at you I was tired as if I was the one running the marathon.

xoxo