Why don't you collect some Super Value stamps. Went to Galway in November with them. €199 for 3 nights 1 dinner mid-week, or for the same price you can go 2 nights, 1 dinner weekend.
You can go on their site to view. You can even book without having the card full. Just have it full before you go...
Stayed in the Westwood House Hotel, great service and food. You can bring children for free or little I think....
Found something that looks good - Spiddal Holiday Homes. Only E240 for a cottage for a week in the first months of the year! Has playgrounds for kiddies on site etc. Seems perfect!