Ireland can be rainy and chilly year round! Bring a light jacket for the trip and wedding. Just the ceremony will be outside (we hope!), while the dinner and reception will all be indoors. Can also bring a pair of wellies if you'll be doing some exploring.
A passport :) On your way back to the US, Shannon and Dublin airports also let you go through US customs in Ireland, so it's a super easy trip.
All wedding events will be adult-only. If you need childcare in Ireland, feel free to contact LMM, an Irish-based childcare provider that partners with hotels in the area (hello@lmmcare.com).