"Then you will be the sweet sister we have known so long."

Mildred is a sweet little sister and I am sure you would love her.

He never did have any patience, no more than you, sweet sister.

Your sweet little sister is right here, next to me.

"Do I have my sweet sister to thank for that?"

"My sweet sister might have a word or two to say about that!"

I did some research, and it's quite possible that my sweet sister could live another five years.

She said, "What is the name of your sweet sister?"

"How nice of you to say so, my sweet sister."

We might never have seen you at all but for your sweet sister.