The Hollow Places, by T. Kingfisher

Second paragraph of third chapter:

When we closed up at six, he’d say, “Good job today, Carrot. Don’t know what I did without you.” Then he would go home and I would go next door to the coffee shop and leech on the Wi-Fi. If I could think of something fun to say, I’d update the museum’s social media. I had grandiose visions of overhauling the web page and doing more with it than the occasional blog post about the history of Feejee Mermaids, but I hadn’t quite gotten there yet. And you had to be careful when you posted pictures of skulls and taxidermy because there were always people who wanted to tell you that this made you a murderer and the moral equivalent of Ed Gein. My internet armor had been built up in the fanfic battlegrounds and was thus impenetrable, but Uncle Earl was a gentle soul, and I was afraid that someone might hurt his feelings.

One of Ursula Vernon’s books that I had somehow missed, this is about a young woman, recovering from divorce, looking after her uncle’s Wonder Museum and then discovering, together with the gay barista next door, that through a hole in the museum’s wall they have access to numerous other dimensions where Bad Things happen and other Bad Things live and they need to keep our world safe. It’s funny and scary, and the characters are very believably delineated. Another good one. You can get it here.