Cicatrix - 1. New tissue that forms over a wound. 2. Botany. A scar left by a fallen leaf, seed, etc.
Fleur and Gabrielle Delacour had always been close. Despite the gap in their ages, they had always enjoyed one another's company.
(When Gabrielle was little, she once called Fleur Maman by mistake)
The Triwizard Tournament ruined that for them. Fleur's inability to save Gabrielle from the merpeople caused a rift between them. It burdened the elder with guilt and shattered the younger's trust.
(A real Maman would rather have died than left her there to be rescued by someone else)
Over time, they managed to throw off their shackles of insecurity. Their bond healed and renewed itself.
(Sort of.)