"Surpise gift!!" joke

Miss Jones is a kindergarten teacher and today is her birthday. As she walked into her classroom one of her students, Dollly, had brought a gift up to her desk.
"Guess what it is!" said Dolly.
Knowing that Dolly's father owned a bookstore she guessed, "A Book?"
"How did you know?" asked Dolly
Next, Robert brought a gift up to Miss Smith. "Guess what it is!" said Robert.
Knowing that his parents owned a florist shop, she guessed, "Flowers?"
"How did you know ?" asked Robert
Finally, Johnny brought up a gift for Miss Smith.
"Guess what it is!" said Johnny.
Knowing that Johnny's father owned a liquor store, and seeing that the bag was wet, she placed her fingers on the liquid and then licked them.
"Rum?" guessed Miss Smith.
"No" said Johnny.
She tasted again..."Vodka?" she guessed.
"No" said Johnny.
Once again she wet her fingers and tasted, "I know," said Miss Smith, "It's wine."
"No!" said Johnny..."it's a puppy."