“I loved America very much and wouldn’t mind at some point returning there myself as my marriage broke down several years ago. I don’t know if I would ever make the move, but if so, could I make use of my green card? I know it’s a long-shot, but perhaps the U.S. looks kindly upon people who used to live there legally and want to do so again.”
The green card that you had several decades back lost its validity a long, long time ago. Once a permanent resident leaves the U.S. and does not take steps to protect legal status for future use the status becomes null and void, as does the green card that proved a legal right to live and work here.
Therefore, just because you were legal for 10 years in the past, your daughter won’t be able to claim any future U.S. immigration benefit because of this.
And to also answer your last question, you too won’t be able to reclaim your old green card. You would have to apply again from scratch, and as you likely know becoming legal in the U.S. now is considerably more difficult than it was back when you were first here.
There are basically three ways to legally emigrate to the U.S. – through an employment offer, winning one of the annual lottery green cards or having a U.S. citizen/permanent resident family member act as a sponsor.
And that brings us to your middle question. You’ve got two siblings who are U.S. citizens, and siblings can act as sponsors. However, the processing time is in the region of 10 years and longer.
If you’re thinking about coming here in the future – way in the future – it wouldn’t be a bad idea to have a sibling submit paperwork to the U.S. Citizenship and Immigration Service (USCIS) on your behalf now. The agency’s website, www.uscis.gov, has comprehensive information on sponsoring family members, and the process isn’t terribly difficult provided there are no extenuating factors – i.e., if the relative has, say, some sort of criminal record.
In the nearer term, with regard to your daughter who wants to relocate here sooner rather than later, your citizen siblings will not be able to sponsor her for a green card.
Though siblings can sponsor other siblings – and, if the sibling is married, the spouse and any minor children (under 21) can also be included on the application – an aunt or uncle is not permitted to act as sponsor for a niece or nephew.
Is your daughter in college or some sort of other course in Ireland? If so she would be eligible to apply for one of the “Irish” J-1 visas which allows applicants to remain in the U.S. for a year of work experience. If this is the case, visit http://dublin.usembassy.gov/general/twelve-month-intern-work-and-travel-pilot-program.html.
The State Department also oversees another J-1 visa website about various internships that could be helpful. It’s at http://j1visa.state.gov/