Upvote:8
It looks as though there are four days on which travel will happen:
If I have that right, you need several round trip tickets:
A travel agent should be able to set all this up, and do seat assignments so that the grandchildren can sit with you on Day 2, and with your daughter on Day 4. It is a bit more complicated than I would recommend trying to book yourself.
Assuming the grandchildren are under 18, do check into requirements, both USA and Ireland, for permission for minors to travel with one parent or with a non-parent relative.