I have taken several day trips out of Dublin. Can't remember the providers, but found them in Rick Steves book for Ireland (any Borders or Barnes and Noble; his website is www.ricksteves.com
- you can order books direct). Challenge is whether these tours leave too early/late in the day to meet sailing schedules.
Dublin also has a great hop on/off bus with 20 stops - very user-friendly city - bet your daughter could walk just about anywhere.
Belfast is an all-day trip I wouldn't risk out of Dublin on a day stop; I saw 2 guys miss their flights because the roads were so unpredictable. Too bad, because touring the area of "the troubles" was incredible.
Pam (brand new)