I have a twin sister. Her name is Tan Mei. On Sunday we went to a park together. Tan Mei left her coat on a chair while we were talking to some friends. When we went back to the chair, a girl in a yellow T-shirt was sitting there. She had some money in her hand. When she saw us, she stood up and walked away. 

I was very surprised, so I asked my sister, "Did you have any money in your coat?"

She said, "Yes, Tan Rui, I did. "

Tan Mei looked in her coat, but her money was not there. 

"That girl stole it!" I said, and we both ran after her. We caught her quickly.

We were very angry. My sister shouted, "Give me the money. " The girl gave the money to Tan Mei and ran away. We both ran after her, but we lost her.

So we were rileyand went home at last. But before we could tell our parents, my mother said to Tan Mei, "You left your money at home. It's on the table in the sitting room. You must be more careful with money. "

So the girl in the yellow T-shirt was not a thief (小偷)! She probably thought we were thieves! We felt terrible. 

We were very sorry for our mistake. We would like to say sorry to her and give the money back to her.