I don't have a copy, so I don't know the answer to this, but by whom was it published? Is there a trademark statement somewhere on the inside of the book? I know that the proceeds went to the "Gygax Memorial Fund", and such was stated prominently on the cover, but that's very different from actually saying that "Gygax" was a brand under which the book was sold (i.e., "used in commerce"). I also don't see a ™ on the cover next to the name, so that makes it even more dicey.
Gail would be infinitely better off actually registering the trademark with the USPTO, in my opinion. It would clear up a lot of issues and give her firmer ground on which to stand, but even then wouldn't absolutely ban everyone from using Gary's name without permission. There's "fair use" in relation to trademarks as well. (Again, I'm not a lawyer, and this is just a layman's opinion.)
Apologies for the mini threadjack into the realms of IP law. I'm done now, pending more news on the magazine and company. I remain cautiously optimistic, but less cautious than I was yesterday.