Not impenetrable, before electric lighting there's a lot more light sources at head height or lower. But she could make that aesthetic work if she put her mind to it.
A world without modern lighting is downright incomprehensible to modern people.
Like, torches suck. They're just pretty bad at actually lighting stuff up. I went on a walk with just a torch for silvester in the vicinity of a small village, and I'm honestly not sure whether the extra light was worth fouling my nightsight. Probably more helpfull on a night with less moonlight and further from other lightsources, but still not that great.
There's a reason why people thought the night was the worst, scariest thing. You just couldn't see shit. People regularly died because they stumbled on something and fell into a ditch. And that mysterious figure could be anyone until they actually said something.
EDIT: Thinking about it, this is one aspect where people are genuinely different. All the big ticket items? Society, culture, religion, money, politics? It feels so very familiar when you read accounts. People drew dicks on walls two thousand years ago, excused themselves from unwanted parties because they had to embalm grandma four thousand years ago, and complained about shitty merchants five thousand years ago. It feels like you could replace a few words, and then people could swap watercooler stories with no one noticing a difference.
But some of those subtle things that are so fundamental that you never see them, they have changed. Lighting is one. That you can have whatever food you want, fresh and whenever, might be another. And the presence of clocks everywhere and the corresponding awareness of fine slices of time is another.