6 nights in Ireland with teenagers summer 2023 - need advice

Allowing for getting too and from Dublin, the 3 nights is only effectively going to be 2 and bits on either side... Don't try and push in too much...

A completely off the wall suggestion - how about spending that time on the Aran Islands ? I think this might meet your criterion of something amazing?

Websites for accommodation on the different islands below.

https://www.aranislands.ie/inis-mor-inishmore-island/inis-mor-island-accommodation

https://www.aranislands.ie/inis-meain-island/inis-meain-island-accommodation

https://www.aranislands.ie/inis-oirr-island/inis-oirr-island-accommodation

We lived in Dublin for two years and traveled extensively around the country. I found the BEST experiences were our air bnb farm stays. We would find a neat airbnb and base ourselves there to explore different parts of the country. With three nights, I would pick one place and make it your base, instead of trying to see too much. I have links to all of the places we stayed and would be happy to give you insight as to what we did within driving distance with the places we stayed. But all of our farm stays involved houses on properties of some really amazing people, who loved to give us tours of their property and loaded with such amazing info. I had a detailed blog....www.irelandwiththefritzes.com, where I kept all travel details. I stopped paying for the domain this year, so I am not sure if all of my photos and info are still stored there. But let me know if you have any questions and I am happy to help! :)

If Skellig Michael and the west of Ireland is your priority then why not just go there directly from Scotland and skip Dublin altogether this trip?
There are direct flights from Edinburgh to Shannon and thence from Shannon on to London, thus allowing you to make the best use of your very limited time to see what's generally considered one of the prettiest parts of the country, and without the need to waste a lot of your time just relocating from place to place.
If you do decide to base yourselves in Kenmare (good choice) I'd suggest devoting a full day or two to the exquisite Beara peninsula just to the south of the town. It features much of the same beautiful scenery you'll experience along the ROK but without the crowds. There are a number of excellent hikes all around the peninsula, including one out on Dursey island which is accessed via the only cable car in Ireland - one of our personal favorites. There's also a nice hike to an abandoned famine village located near the center of the peninsula if you're interested.
The suggestion to spend time on one of the Aran islands is a good one. It would be an easy drive up the coast from Dingle or Killarney to Galway, where you could turn in your car and catch the ferry or a flight over to Inishmore, then train back in to Dublin for a day or two before proceeding on to London if that's your preference.

It would help to know your family’s interests because there are a number of amazing experiences depending on your interests (traditional music in a small town pub, prehistoric sites, Kilmainham Gaol in Dublin, General Post Office Museum in Dublin, sea kayaking in a bay, hiking along coastal cliffs, etc.

Skelling Michael is an amazing experience just in and of itself, and if any of your family are Star Wars fans, that adds another dimension. Visiting it takes a full day; you need to arrive early to catch the boats, so it helps to be nearby the night before. Kenmare is perhaps a 2 hour drive from the landing at Portmagee. Driving from Dublin to Kenmare will take up a good part of a day. So if you want to visit Skelling Michael and see the Kenmare area, that will probably take up most of your non-Dublin time.

Some of my best experiences were staying in family run AirBnb’s and getting to talk with the hosts about their part of Ireland and their experiences.

All the best,

Raymond