Advice about translation in Cymraeg and Gaelic needed.

[BadbCatha]

I'm writing some fantasy sentences (currently, about 560000 chars), but, to keep it simple, I set them in North Wales.

 

I'm wondering if in the forum there are people who know Cymraeg or Gaelic and are so kind to give me some needed advice for some translation.

 

Here there are the more compelling:

 

I need to translate "An Ancient Path" and managed to put together "Hen Llwybr", but I would appreciate some control.

 

And I need the Gaelic form of "Ann O'Reilly". I've red, some times ago, a page about the transformations that the family names takes when they come after the word "Ní", and I understand (at least, it seems to me) that If the first letter is "R" the pronunciation actually changes, but not the spelling. So, I've found "Aine Ní Raghallaigh", but I would your advice about this, too.

 

Thank you for your attention.