Hi there,
when you come out of the Elmbrook Estate and take a left turn and keep walking straight you will see that there are railings and a little park area to the right, if you keep walking straight at the end of this park area there is a footbridge that takes you over the N4 and onto the other side out to Woodville. Then when you come out of the Woodville estate (by walking straight) Lucan village and St Marys School is down to your left. In total its about 15/20 min walk to St Marys and less to the school at Woodville (unfortunately I don't know the name of that). There is also an Educate Together School about 2 mins walk from Elmbrook and a very good Irish School about 5 mins away at the back of Esker Meadown estate. I believe you are eligible for all of these when living in Elmbrook. I live close by and if I had kids my first choice would be the Irish School, although I have heard good things about St. Marys. I hope this helps your friend!