You might check out the seal rescue programs as you may do able to help release a seal or to back into the sea. My great nephew and neice did this at ages 5 and 7..Shouldn't be too young for yours. mine loved it. Waterford doesn't offer much IMO. I take it May is the month.. Still will be cool and of course the kiss from the clouds will be accompaning you..

Why not fly into Shannon out of Dublin?
The Cliffs are so safe now you have a 4 ft wall 10ft back from the edge so you cant even see the edge in places.
Kilkenny is worth visiting but if your aim for Waterford is the crystal tour see Celtic Crystal in Moycullen on the way into the Connemara,
So from Shannon no jet lag, Bunratty then 2 day base in Ennis which has things for the babe's if it lashes down and gives options for South Clare, Then past the Cliffs, Inis Oirr cruise? and Galway although Clifden would be a better base for Connemara. http://ireland.activeboard.com/t50055177/n59-galway-route/ & http://goo.gl/maps/iSQcB

W/ just one week I certainly wouldn't fly in/out of Dublin. I'd fly in to either Cork or Shannon and home from Shannon (or home from Dublin if you really want to visit Dublin)

Good idea to fly into one city and out of the other so you can see more of the countryside, too. If you need a car rental, check Easy Tour Ireland. I saw they have a special for rentals before May 27 where you can get a free driver or GPS. That is a big savings. http://easytourireland.com/

The girls may be a bit young, but consider a Hawk Walk at Ireland's School of Falconry on the Ashford Castle grounds. http://www.falconry.ie/hawk-walk
My grandsons are still talking about their Walk 3 years later.

More info:

http://www.fodors.com/community/europe/ireland-with-3-12-year-olds.cfm

http://www.markandmonica.com/Travel/Ireland.htm

That last link is a really interesting piece of work and destined to join the few Blogs on my Bookmarks. Thanks.

Not mine btw, but one I saved when researching my own trip.

Thanks everyone! I think we're going to cut out Waterford and spend more time using Galway as a base camp. I wish we could fly in or out of Shannon but our frequent flier miles options didn't work out that way.

I can't find much on Ennis - is it just a central locale for day trips or is there much to do in town!

Ennis is the best Touring base for County Clare as a whole http://www.visitennis.com/what-to-do-category/children-family/ have a look at the site I have linked the family/children portion. Bunratty Folk Park is 30 minutes south the Clare Coast the same time West, Killaloe/Ballina at the foot of Lough Derg the same time East and Coole Park 35 minutes North, Basically there is a whole lot within a one hour radius.

I'm sold on Ennis being a base! Great idea.

Here's what it's looking like now:
5/4: Arrive Dublin mid-day. Stay in Dublin.
5/5: Powerscourt Estate & Gardens. Stay in Dublin.
5/6: Drive - Kilkenny, Cashel, end up in Ennis. Stay in Ennis.
5/7: Bunratty Castle daytrip. Stay in Ennis.
5/8: Drive - Cliffs of Moher, lunch in Galway, Ashford Castle to stay overnight
5/9: Kylemore Abbey (is this worth a visit??). Stay at Ashford Castle.
5/10: Make way back to Dublin. What's a good stop on the way? My husband suggested Trim?

Again, hate having to fly both in and out of Dublin but it really was our only option with the way tickets worked out.

thanks for your feedback on the above! Open and welcome any assistance/criticism!

(p.s. Any recommendations on places to stay in Ennis would be welcomed!)

If you can get a good deal then the Old Ground or Temple Gate then they are right in town. As you have youngsters then perhaps the Auburn Lodge 1 1/2 mile out of town on the Galway Rd would be a good child friendly option with an upgrade room the same price as a basic town centre room. Brogans in town does great value pub grub,

A touring map I did last year for someone staying at Ashford http://goo.gl/maps/L5ihu

The usual stop on the way back east is Clonmacnoise but Trim would work staying in an Airport Hotel.

Those are the two places I was looking at! I'll check on the Auburn Lodge as well, thank you!

Trim is a good option but I'd rather stop in Kildare and check out the National Stud and the Japanese Gardens. Your kids will love it!
As for Kilkenny, definitely a good choice. I think your 3 and 5 year old children would enjoy a hurling tour http://goo.gl/FhuDz and practice the basic skills of this popular Irish sport. The 3 year old may not be able to join in but would certainly be attracted by this interesting activity.
In Dublin, I'd strongly recommend Dublinia, one of the most fun ways to learn about the Vikings and the origins of Dublin. It's a must for kids.
A Viking Splash tour is also a great way to enjoy seeing the sights of Dublin and be entertained!