Do you think it is okay if I scream at my sister?
Why are you mad at her?
Because she stole my cell phone and it made me really mad.
You shouldn't raise your voice to someone like that. Especially if it's your sister.
No one will care, and if they do, I will blame her.
Just tell her what she did was wrong, you don't need to scream. You will look bad if you yell at your own family members instead of just discussing what they did that made you mad.