Also, under the annual small gifts exemption, you can give them €3,000 per year outside the tax system (i.e. it doesn't contribute towards the cumulative sum received that brings them closer to the CAT threshold).
So if they don't actually need a lump sum now, it would be more tax efficient to give them €3,000 p.a. on an ongoing basis - or maybe depending on your age/their age, some of the money as €3,000 pa and the rest as a lump sum when they need it.