Ex-Champ Car driver Legge was discharged from Sainte Anne hospital in Toulon on Tuesday morning after breaking her lower left leg and a bone in her right foot when she crashed the Signatech-run Richard Mille Racing Oreca 07 at the fast Signes right-hander.
The 40-year-old will continue her rehabilitation at a specialist centre in France in order to try to be fit for the Le Mans 24 Hours in September, when she is due to drive the car as part of an all-female line-up with Tatiana Calderon and Sophia Floersch.
Signatech boss Philippe Sinault told Motorsport.com: "Our hope is that Katherine can be fit for Le Mans and we will know more in the next few days.
He said that there was no decision on who would join Alfa Romeo Formula 1 test driver Calderon in the car, which is backed by the FIA Women in Motorsport initiative, for the next round of the ELMS at Spa on August 9.
Floersch is unable to drive at Spa courtesy of the clashing round of the FIA Formula 3 Championship at Silverstone, but is scheduled to join the team for the Barcelona event at the end of August.
"It is the plan at the moment that Sophia will do Barcelona because it is important that she races the car before Le Mans," Sinault said of the event that clashes with the F3 round on the bill of the Belgian Grand Prix at Spa.
#50 Richard Mille Racing Team Oreca 07 - Gibson: Tatiana Calderon, Andre Negrao
Andre Negrao, who races for the Signatech Alpine squad in the FIA World Endurance Championship, was brought in to share with Calderon in the race at Paul Ricard after the Oreca was rebuilt around a new monocoque.
"Bringing in another girl without experience of the car at short notice wasn't realistic, so I rang Andre in Brazil," said Sinault. "I told him we are in trouble and you are part of the family, so he flew in from Sao Paulo."
Negrao and Calderon finished fifth in the four-hour race on the same lap as the winning United Autosports Oreca shared by Alex Brundle, Job van Uitert and Will Owen.
Legge crashed in testing last Wednesday when she got on the kerbs on the exit of Signes.
"The track has been resurfaced and is very smooth, so we can run the minimum ride height," Sinault explained. "With the car in this configuration when you get on the kerbs it is like driving on ice."
Legge's injuries were initially listed as a broken leg and wrist in an official ELMS statement.