I don't believe for a second more than one (exceptionally stupid) person asked where she got those names. Back in the day, maybe, a specific book would be helpful, but this is the age of the internet, where there are a bajillion name sites, and more than a few specifically for Celtic/Gaelic/Irish names.

I swear, just as much as her characters "talk" to her, she has "fans" "ask" her "questions."