Thanks for reaching out. It is great to hear you were able to trace your family roots to County Armagh, have you ever had the chance to visit? We have a dedicated community called Ireland Family History
where you can share your experience, family story or try to find out further information on your Irish roots.
In terms of dual citizenship, if one of your grandparents was born in Ireland, but neither of your parents was born in Ireland, you may become an Irish citizen. You will need to have your birth registered in the Foreign Births Register. You can find out all the information you need on the Citizen Information page here
Let me know if you have any other questions and I would be glad to help out.