Bonjour Barbara,
How exciting that you are coming over to see us with your family! your question isn't silly at all!
Packing for Ireland isn't so difficult - in fact, I would suggest bringing clothes that are easy to layer up or down, as the weather can sometimes be unpredictable. I'd suggest t-shirts, long sleeves (sweat shirts),a short as well as a raincoat, just in case. Do you plan on hiking with your family? A comfy pair of trainers is a must.
Personally I pack breathable clothes that I can easily remove and put in a backpack if it gets too warm and a rainjacket that folds on its own pocket.
As for the weather in July, it is mild between 12 and 20 degrees.
This page will give you forecasts for the next 10 days as well as more general information
To help you further, here's a handy
packing video, a
previous thread on packing as well as a
checklist to help you finalize your trip.
A bientôt et d'ores et déjà un bon voyage,
Antoine