Hiya Wendy .... welcome to the forum .... we first went to Ireland when my 2 kids were 4 & 9, & we never walked much further than you ... plus it was often slow going, but we hit a rare thing in Ireland, a heat wave! So didn't mind the slow pace. On that occasion we were based near Kiillarny, County Kerry & it was stunning, beautiful mountains, lakes, & waterfalls (which the girls loved scrambling up) but we did struggle to find ROW's in Ireland & wish I'd (like you) had researched it better.
Wherever you go - ENJOY.