November Investigation  3rd and 4th graders

Solve this riddle

Two mothers and two daughters went out to eat. Everyone ate one burger, yet only three burgers were eaten in all. How is this possible?

PLEASE LEAVE YOUR ANSWER AS A COMMENT AND MAKE SURE THAT YOU ALSO WRITE YOUR NAME AND YOUR CLASS NAME. THE COMMENTS WILL BE PUBLISHED AT THE END OF THE MONTH AND THEN WE'LL ALSO TELL YOU WHO ARE THE WINNERS. 

 PLEASE DO NOT GOOGLE THE ANSWERS...