I had the exact same problem. I picked out the vanity I wanted but did not think about the fact that it wasn't made to sit flush against the wall. I spent a month looking for something else, but in the end we decided to go with something shorter and have it not be against the wall. But we were going from 72" to 60" which is probably not workable in your mom's situation. I did find a lot of vanities that did have flat sides and could work in a corner, if you are willing to have the countertop fabricated. They just need to not have any trim detail on the top or bottom like the one you picked out does. I would just look at the ones without the pre-made tops. Because the pre-made top will still leave you with a slight gap because of the countertop overhang. This is an example: Avanity Modero which is sold everywhere, not just at Lowe's. The cabinet we ended up buying is an Avanity Madison which won't work for you, but I assume it is of similar quality. We are pretty happy with it. The drawers and doors have soft close but I do feel like the glides in my Ikea kitchen drawers are better quality. It is very pretty and I wanted a stained wood so I am really happy with our choice. If I had been willing to go with a painted finish, I think we might have stuck with the 72" Modero.

At the high end, cost is for style and function. Check your local code before purchasing toilets and faucets; e.g., California has restrictions on water flow (GPM) and flush rate due to water conservation, which narrows the choices. I have recommendations for quality faucets. I chose Samuel Heath in my master bathroom. Plumber complained about my purchasing fixtures from "across the pond," but there was no problem with deliveries. For the guest bathroom, I chose Kallista (high-end of Kohler), made in U.S., but had considered Fantini (also from "across the pond"). Rohl offers a range of faucets by various manufacturers; Rohl Perrin is on the high-end. For my hallway bathroom, I'm considering Dornbract, Graff, California Faucets, MGS, and Hansgrohe. There are many other quality faucets that may not meet CA requirements, such as Newform, Italbrass, Rubinet, Watermark, and Barber Wilson In general, for high quality, avoid products from "across the other pond."

"When you say "trim pieces" are you referring to the visible faucet and handles?" Yes, here are the American Standard Roman Tub Deck Mount trims on build.com. Each trim requires an American Standard rough-in valve. There are many trims but only a few valves. If the new trim requires the same rough-in valve as the old, you can switch it out without changing the valve. For example, the Studio S and Delancy trims require the same R900 rough-in valve (click the linked Specifications document for each trim) even though they look nothing alike. But you cannot change trim brands without changing the rough-in valve.

Thanks for the reply. I'd rather not replace this fixture. Just need the 5.25" glass cube shade, which I'm currently looking for. Of course, it'd help to know the make and model, which is why I figured I'd try my luck and post here. Thanks, though.