Was the agreement between the two girls to give the winner a piece of chocolate from one side considered a forbidden wager?

Betting on money is permissible in what the Sharia has allowed, such as races involving horses, camels, archery, and beneficial sciences. Ibn al-Qayyim, the followers of Abu Hanifa, and Sheikh al-Islam Ibn Taymiyyah held the view that the permissibility of betting on knowledge and argumentation is more appropriate and deserving. As for other games, competition for a prize is prohibited, unless it is an unbinding promise of a gift. Silence about what does not concern one is acquired through striving, practice, and reading about its virtues.