That article seems way off-beam to me and very Brexiteerish. She's arguing against a GNU on the basis that it takes power away from the people and turns it into a "professional decision" for MPs. But from the moment that the referendum result came in as a more-or-less equal split, it's always been exactly that i.e., how do you actually enact this thing for which the public has (just about) expressed its support but for which there is no clear roadmap? Various factions have tried to pull the Brexit process towards their own political ends to get the type of brexit they want (and which they claim is thewillofthepeople(TM)). GNU is an attempt to prevent individual minority factions from hijacking the process precisely because it forces people to cooperate.
"Just like the denial of authority to the seventeen million or so citizens who voted Brexit, the denial of dignity to the half-million Labour members represented by Corbyn reveals the enduring inability of pro-Remain elites to comprehend, let alone relate to, opinions they oppose."
What utter balls. The majority of Labour voters voted to remain, so suggesting that "pro-Remain elites" don't understand the concerns of people who also voted remain is just nonsensical. More to the point, most remain voters (let alone voters in general) are not Corbynites so any coalition/GNU that actually wants to build unity (around a remain platform or otherwise), should be headed by someone who is less clearly divisive.