Meaning: A young female child obtained a sweet food made with sugar by paying money for it using a small, round piece of metal used as money.
Choice of Words: The word "girl" refers to a young female child. "Bought" means to obtain something by paying money for it. "Candy" is a sweet food made with sugar. "With" means using or accompanied by. "Coin" refers to a small, round piece of metal used as money.