If someone is a non dom and makes a gift to children at the time of being non dom and then becomes dom within five years, should the person die before the seventh year are such gifts subject to IHT?
If the asset gifted is not a UK situs asset then the gift is one of excluded property and is not within any IHT charge.
If the gift is a UK situs asset to another individual then the gift is a PET and an IHT charge arises if the donor dies within 7 years.The nil rate band may apply which means any IHT is charged at 0% (ie no IHT).
Becoming "dom" is not the same as becoming "resident". Can you give more details? Where is the "non dom" and how long have they been there? What makes you think they have become "dom" after just 5 years?