There are two questions, quite similar.
I know the word twin which means one of the twins. Now, while introducing a girl to my friend, I want to say, "she's a twin" but in this sentence only, I want to tell that who is the other twin of that twins.
She's a twin to her brother OR She's a twin to her sister
Is it fine? Now the second question...
Do I need to put other/another in this case?
She (A) and her brother (B) are twins. She has one more brother (C) but while introducing, she's with her non-twin brother (C). Should I say...
She's a twin to her another/other brother?
Is that okay? If not, how do we say that?