Interesting. Quite a lot of names of animals, not just wee ones, have names with a diminutive ending. When it's not easy to tell the sex of the animal (as with a kitten - have you ever tried?) then it seems that a diminutive suffix is added arbitrarily
so by chance we have a masculine word for kitten in Irish and a feminine one in Gaelic.
That is because English requires all singular nouns to have an article or determiner of some kind. This rule doesn’t exist in Gaelic. So in Gaelic, the noun alone (indefinite) is the equivalent of using the noun in English + the indefinite article “a”.
It’s not going to translate word for word. Most languages don’t.