How many days in Dublin?

The Rick Steves guide to Ireland lists things to see and do in Dublin with a point system, giving the most points to the ones most popular or considered "must see." Naturally your own interests and those of your daughters should be taken into account.

If you have 8 days, is that 6 nights? Or do you mean 8 days on the ground in Ireland not counting travel to and from?

Either way, there are numerous points of interest within an easy day trip of Dublin, so you could stay in the same hotel or B&B the entire time and still get a good taste of both the city and some areas in the countryside.

If you have 7-8 nights in Ireland, you could fit in 2N in another town if it's one bus or train away. In that case, better to go straight there on landing and have all your Dublin nights together at the end, so you are close to the airport the night before your flight.

There's plenty to do in Dublin itself, and you can arrange day trips to some of the highlights in the countryside as well. Dublin has fine museums, 2 theatres with London-quality performances (plays, not grand musical shows), two9 cathedrals, and parks.

Some of my faves were the Dublin Literary Pub Crawl, the Archaeology Museum (it's a wow), Dublinia (it's a serious museum with a lot of fun hand's-on stuff). My one regret is that I missed Kilmainham Gaol.

Thank you for the great advice!

This is probably blasphemy to many folks, but some would argue that Ireland's best attractions (and certainly its best scenery) is found away from the big cities. We did a trip just a little longer than yours, and we only spent one night in Dublin (our last night, since we had an early flight departing the next morning). The rest of our time we spent on the west coast and southwest of the country. We loved every bit of what we did and saw. We know we will return to Ireland for subsequent trips, and we will probably spend more time in Dublin (but also want to visit other parts of the country).

Although Dublin certainly has its charms, if you've got roughly a week, I think it would be a shame to spend all of it in Dublin or any city. As Chani suggested, upon arrival in Dublin, you might grab a bus to Galway, on Ireland's west coast (get the bus at the airport, easy and comfy), and press on to there rather than try and struggle with things when you're exhausted (most flights from North America arrive in the morning, this makes a good use of your first, jetlagged day). From Galway, there's plenty of good things to see and do for a few days. Then back to Dublin for as many days as you choose, and you're ready to catch your flight home.

Agree with David. Head to Galway upon arrival - either by train or bus - and settle in there for a few days.
Am guessing that you don't want to rent a car, in which case there are several good day trips that originate in Galway to keep you occupied and introduce you to the beauty of the west of Ireland. One excursion that you can organize on your own is a day trip (or better yet an overnighter) out to Inishmore. The ferry landing is at Rossaveal about an hour north of the city and the company http://www.aranislandferries.com/ operates a shuttle service (for a fee) to get you there and back. Couldn't be easier. Others here have suggested flying which looks like a reasonably cost-effective alternative to the boat ride. Here's the link https://aerarannislands.ie/.
After 3 or 4 nights in Connemara you can catch the return train into Dublin and enjoy the city for a few days. There are organized tours north to Newgrange, Tara and the Boyne Valley, and south to Powerscourt, Glendalough and the Wicklow Mountains.
You could also travel independently by train to Kilkenny or up to Belfast for the excellent Titanic Museum there.
Belfast might be an alternative to Galway if you want to spend a few days in the fascinating city, with day trips up to Derry and the Causeway Coast. There are also companies that specialise in tours to Game of Thrones film locations, of which there are quite a few close to the city.

To me, Dublin itself is worth 2 full days at most, the rest of the time can be spent either on day trips (like Glendalough or Trim), or splitting time in another city.

Belfast is a great day trip from Dublin. The other suggestions above are great too. Just be sure to be back in Dublin, the night before you fly home the next day.

Thanks all for the great advice. I may even look at flying into Shannon instead of Dublin - will give us more time in the west, and then seems an easy train or bus ride to Dublin for the end of the trip.