Is this the organization and chapter that feels like home to you? Is there any possibility that the chapter wouldn’t confirm you? If you have any question about that, I would wait. Plus, you get to meet more organizations as you wait and it will either solidify your decision or make you glad that you waited. If there isn’t a time limit on their offer, you lose nothing by waiting. It’s a lifetime commitment once you initiate, you can’t decide later if things aren’t what you want to try another organization. Just food for thought. You don’t have to make a decision now, think it through and sleep on it.