Surgical intervention on France: insurance (Paris)

Hello,
My mother in law is visiting from China. She might need surgical intervention. It is not an emergency but she would like to, given the fact that visiting a hospital in China is all but convenient: dozen of hours of standing in line is not rare, with no guarantee of actually seeing a doctor.

Would you know of an insurance that she could get in order to reduce the costs? If she needs to pay all by herself, that will probably be very expensive.

Thank you for any information.

Jerome