Hi Swordsmami,
There is a great playground in Donabate, at Newbridge Farm. There is a picnic area and when the weather is nice there are lots of families with children there. It is free for the picnic area and playground but there is a small fee to go into the farm, although it is worth it as the children can feed the pigs and goats and see baby chicks and peacocks. Its great!
There is also a wonderful playground in Ardgillen Castle, which is also quite near to you. It is between Skerries and Balbriggan. There is a picnic area there also and a coffee shop and beautiful grounds for the children to run around. It is free entry.
There is a Sibin festival in Balbriggan on 2nd May that your children might enjoy. See http://www.balbriggan.net for more information on that.
In the Pavilions shopping centrein Swords there is a creche beside Ladybird. You can leave you child in for regular morning sessions with other children, or if you are doing some shopping, you can leave you child in for 1-2 hours. It costs 5 euro per hour but there are special rates if you leave your child in a few days a week.
I hope some of that helps – perhaps you could also log onto the Dublin chat and see if there are other mammies in your area who would also like to meet up.
Louth has been running for a while which is why there are so many mammies on here but when mammies like you start posting on the Dublin chat, that will grow too and you will be able to find out about local mother & toddler groups that perhaps we do not know about.
I hope some of that is helpful!
Good luck!