I generally name all of my buildings. If it is a business, the names are directly on the front (or side) of the building and some are on signs out front. I'm working on a Victorian boarding house, and am thinking about naming it Miss Bertha's Board House. A scratch builder friend of mine said the name would be better using her last name; ie. Miss Smith's (or any other sir name)Boarding House because it would appeal to the masses. Growing up in the 1950's, I was taught you call older ladies by Miss and their first name.
Depends on how "prototypical" you want to be. You can Google search for boarding houses of a certain period and find out how some of them were named. Also there may be some regional differences -- for instance, the "Miss Firstname" custom being more common in the South, perhaps, than in other regions.
However, there are always exceptions, so whatever you choose would not be incorrect. And of course there's also Rule #1: "It's my railroad, I'll do what I want."