Just so that you know, the Irish don't do bridal showers, so you needn't think about emulating a typical menu. I agree that tea foods are probably best.
No one here has mentioned the one item that would be guaranteed to be on the menu at a festive tea in an Irish household: FRUITCAKE!!!! No festive occasion in Ireland is complete without it. (For weddings and Christmas we have iced versions with almond paste marzipan and royal icing on.)
As to fruit flavorings for jams, scones or such, the most popular in Ireland would be red currant, followed probably by apricot and apple. Cream pastries are also very popular, as dairy products in Ireland are of VERY high quality, so they are always quite delicious.
I'd also recommend some smoked salmon, always present if you are pulling out all the stops for a party menu. Quiche turns up quite often, too, as French influence is very strong in Irish cuisine these days. If you want to include a food that looks green, I'd go with egg and cress tea sandwiches; those are eaten everywhere in Ireland and the UK.