There seems to be nothing to support Alice being called de Gurnon or de Gurnons In either Medlands or Wikipaedia and her name in the curator's note at the top of the profile gives her name as Alice of Chester so I have changed her name to this and hope that if any documents appear supporting the de Gurnon name as a result of this discussion then we can revisit which name is most appropriate.
It is noted that her brother Ranulph is called de Gurnon as that is where he was born and it is possible that she too was born there.