Indeed, I think DrJ may be correct on that one CZ. Iníon (in-EE-on) is specifically the word for daughter, mac being the word for “son”, hence the prevalence of surnames beginning with Mac/Mc, common in Ireland, but very common in Scots Gaelic.
Then of course, there is Fitz…which can be traced back to the French fils for son. But it’s use in the surnames Fitzpatrick and Fitzgerald (or hey, is it FitzPatrick or FitzGerald) is one example of mega-convoluted differences in Gaelic surname origins.
I’m also not sure there’s a common root in pre-Anglo-Saxon British either. Irish Gaelic is thought to date from around thousand-ishBC when the first Celtic settlers arrived on the island, evolving into ancient Gaelic, then splitting into Scots and Manx after they got bored of fighting amongst themselves and headed back East for a bit of pillaging, and hung around for a while.
Europe’s oldest literature written in the tongue of the people is that of the earliest Irish writers.
I spoke Irish fluently when I was younger, as did my mum and sister (but never as a first tongue) which is great but I’m still glad that the British and Normans left us with English as our “first” language when they finally left. 🙂