14 days in West/Northwest Ireland

Aloha Anthea. That sounds reasonable. My first trip to Ireland (47 years ago) was not as long, and I was moving a lot more than your plan, though being in my 20's allowed for more movement.. I also didn't mind not knowing where I was going to stay. I spent a full day in Dublin (I came from England, so jet lag was not a problem - jet lag is real, especially for us older guys). I drove clockwise with my first goal being the Ring of Kerry for a couple of nights, then a couple of days to get to Galway and a couple of days around Galway, before taking the train back to Dublin. It sounds like you're planning a more sensible trip and I think it sounds very reasonable. Rick's Ireland tour book is great (I'm going in early April). I recommend getting it - I know I learned a lot and I know Ireland a bit.
Your father lucky to have you as his tour leader! Bon Voyage.
Kevin

Not sure if this is your first trip, and I don't know what you like (music, hiking, views, foodie, museums) but my feedback would include (and understand we travel fast and light, which is not what some prefer):
1) You could hit New Grange on the way to Galway to save a day trip at the end.
2) We love Galway, but you'll run out of things to do in four days. You could head to Connemara as a day trip, but it would be easier on the way to Sligo. Same for Clifden and Westport. Maybe an overnight on Inishmor?
3) Never been to Sligo (will be there in 2026) but we loved Donegal, but three days is a lot of time.
4) Again, three days is a bit much for Dunfanaghy. Doe Castle, Glenveagh NP, the Workhouse, Horn Head, are all nice, but town only has a few bars, scarce music, and little to do.

My itinerary would be something like
Dublin, one night (depending on where you're flying from, going straight to Cavan might be practical)
Cavan or Cong one night (to let you get an early ferry to Inishmore)
Inishmore one night
Galway three nights
Clifden or Westport one night
Sligo 2 nights
Dunfanaghy two nights
Dublin, three nights.

I like your itinerary. It is relaxed and gives you at least 2 full days in each place. Ireland is a place to slow down and relax. Driving is slow and you need to build in time to just stop and stare...

We spent a week in Donegal and still hadn't scratched the surface. It is the place to just follow your nose, explore (maybe get lost)... There are places off the tourist radar like the derelict 'marble church' at Dunlewy, built as a memorial to to a great love affair between James Russell, the landlord of the Dunlewey estate, and his wife Jane- Ireland's own Taj Mahal?

Gleneagh National Park and castle are well worth visiting. The coast line with its small villages is delightful. Don't miss Slieve League cliffs . Nearby is Glencomcille with the carved crosses scattered round the village and the carefull restored Folk village complete with thatched cottages.

On the way from Dublin to Glendalough, think about a visit to the early Christian site of Clonmacnoise with its ruined chapels, round tours and carved crosses.

We have always loved County Galway.
Athenry, a small walled town with ruined castle and priory is just a short drive from Galway and is worth a visit.

If in or around Headford, go and find the ruined Ross Errily Friary on the banks of the River Shannon. It is well off the usual tourist trail and delightful.

Cong also has a ruined abbey and also the monk's fishing station on the river complete with bell to ring to let the kitchen know if a fish had been caught. The 1952 film, The Quiet Man staring John Wayne and Maureen O'Hara was filmed in Cong. The Quiet Man Museum is a replica of the cottage used in the movie and is popular with American visitors.

On your way from Galway to Sligo, you might want to make a short detour to the National Museum Of Ireland, near Castlebar. This is a fascinating folk museum with lots of information about life in Ireland over the last 150 years. There are lots of short films made in the 1960s recording people's way of life and traditions.