I think logically whether she lives in Ireland or not, if you were to die your estate is subject to Irish law and if she was the beneficiary she would need to say she already received 300K of her Irish CAT allowance. So why not give her the €300K now and let her worry about CAT tax after you die.
It’s reasonable to assume that CAT thresholds will be higher in a few decades time.
Even if not in the meantime your daughter will have the benefit of the wealth so it makes sense to transfer sooner so it grows in her name and not yours.