Penelope's irish accent

Apologies if this has been asked here before or elsewhere. I'm on a rewatch while I wait for part 2 of season 4 (cant it be released tomorrow?).

Season 2 1st episode, the scene where she is talking to the guy at the printing press. She puts on an accent while impersonating someone who works for lady whistledown.

Now, I know Penelope reads, but back then they had no access to media or anything of that sort. Neither are we introduced to any irish characters around her. How does she know that accent?

Am I dissecting too much at this point? 😂