----- Not an ESL teacher -----
Does the ''girl'' in the following sentence also mean ''girlfriend''?
She is my girl.
Thanks.
When I read the title of your thread, before reading your initial post, I thought about it as "girlfriend." In a romantic way. That is the first thing which came to my mind.
Then, by reading your post, I had to stop to think about it.
Usually yes, but not necessarily. It is somewhat of an affective way of expressing a relationship (although someone may object that it also expresses a "possessive" feeling implying some prejudice).
You could also use "She is my girl" to refer to your fianceé, wife, or even your daughter.