After the event, you and your girls will return to the events committee to evaluate the event. Prior to this meeting, you will want to talk with the girls about how it went, get specifics about what worked well and what they would change next time, evaluate the budget, and decide whether or not they want to do another event in the future. At the events committee meeting, we'll ask for a brief summary of your evaluation.
Part of your troop evaluation (before the meeting) will be to reconcile the budget with the service unit treasurer. If the event is a fundraiser for your troop, you'll need to make sure your records match the treasurer's for the amount of income. If it's not a fundraiser (the service unit is financially responsible), you'll need to reconcile both income and expenses.
After the evaluation meeting, the event is officially done.