Philippa, the 'gile' vs 'ghile' quarrel is easily resolved. In Irish, when you use the word 'mo' (meaning 'my'), the first letter of the word after it is softened, the pronunciation changed. In modern Irish spelling this is rendered by adding an 'h' after the letter.

So it's croí (heart) but mo chroí, and so on. Adjectives are also softened in this way. The grammatical term is either lenition or ellision - I can never remember which is which.

(In our grandparents' day this was done by putting a 'buailte' over the letter - a dot - which was a survival of a kind of shorthand invented by the Irish poets who were thrown into the life of a labourer by the seizure of their patrons' lands. They spent their nights, after a long day's labouring for some etiolated think-skinned poet, writing out the poetry that had been many thousands of years in the culture. But because they were scribing by rushlight and in a state of exhaustion, they used a shorthand they invented and agreed. The 'buailte' replacing the earlier 'h' was part of this, and survived into the early 20th century.)