Alastriona (ah-lah-STREE-nah, al-iss-TREE-nah) is the Irish version of the Greek girls name Alexandra, meaning "defender of man." It is just a bit different from Alasdair/Alastair, the form of Alexander. Many might be intimidated by the Irish spelling, but a simple explanation that the O is silent would clear things up, or you could use the Anglicized spelling Alastrina. This is an extremely rare name in the U. S. with no data Her native nickname is Triona (TREE-nah), but I don't see why other nicknames wouldn't work in the U. S. like Aliss, Listy, Lass, Allie, or even Alina/Lina. Ailstreena is the Manx form.