I don't recall her having any particular language skills (although I would bet she knows a wide variety of swear words). Her time as a foreign exchange student was spent in a country that speaks English (Ireland) and I highly doubt she bothered to learn Gaelic. She may have picked up a word or two if it suits your purposes.

If you need her to be able to speak something, though, I don't think it would be too difficult. She might not be fluent enough to pass for a native, but it's conceivable that she took a foreign language in either high school or college.

Lois: You know, I have a funny feeling that you didn't tell me your biggest secret.

Clark: Well, just to put your little mind at ease, Lois, you're right.
Ides of Metropolis