So instead of studying for my exam tomorrow, I've been researching this illiomancer. I found two that almost fit the description.
English, could have painted between 1910 and 1920, in a guild of crafters (the Birmingham Group and the Royal Birmingham Society of Artists), skilled in other crafts (wood engraving, stained-glass windows, writing, etc.), and daughter Barbara Sleigh was a children's writer. Bonus: he was into fairies, elves, and all kinds of magical creatures.
Another person that almost fits:
English born, could have painted between 1910 and 1915 only, part of the Arts and Crafts movement, skilled in the craft of wood-engraving, had a daughter named Beatrice Crane that potentially did some writing (can't confirm this 100%), has a piece of art in Merseyside called The Triumph of Spring
Seems like our clues could apply to quite a few people. I've been trying keywords in the book, but others should keep trying.
As for the clues, I would think they are still good for any fragment (I hope), and I thought we were supposed to receive more clues after each fragment is unlocked, but I'm not 100% sure.
I'll keep looking.