Romance of a Shop, overall, is really great. Each sister has different ways to shine and altogether the plot is very entertaining as they try to balance sustaining themselves financially with art, and advancing their personal lives. There are a few points where I think Levy's writing struggles from a technical standpoint, but also other moments where she totally nails it (especially the final confrontation scene between Gertrude and Darrell). I also think she leans a little too hard into moments of the female characters criticizing the other women for things they can't control (Fanny, the Girtonian girl, etc) but not a big deal, in the grand scheme of things.
My main issue is how she handles Gertrude's ending. When I initially finished the book, I was quite upset with how she chose to conclude Gertrude's story. Not that I don't like Lord Watergate, I really enjoy his ability to portray good men (similarly to Frank Jermyn), but it definitely didn't feel right at first for her to end up with him. So many moments throughout the novel point to Gertrude being uninterested in men or marriage, either not foreseeing it for herself or not wanting it for the people around her, and additionally (like other critics of the time) I was annoyed that every woman in the novel either ends up married or dead--RIP Phyllis. It really undermined the New Woman messaging that I thought Levy was going for.
On further review, however, I understand it a little better. Not only does Levy challenge the reader not to accept one standard idea of what the liberated woman can become, its also coming from a deeply personal place of the author wanting someone who can love her. Levy's life ended in tragedy and knowing that, its easy to see how she projected her desire to be understood and comforted onto Gertrude.
TLDR: Really good example from the era of the New Woman movement starting to take shape, but also interesting to read it with a critical eye and look deeper than just what interpretation Levy wants the reader to come away with. Or you can treat it as a lighthearted story about art, sisterhood, and perspective.