Tetanus like symptom for a recent mother

My sister gave born to a baby 2.5 months ago. Since from the delivery, she has been suffering from severe tooth pain. Dentist said that the tooth should be taken off since it was infected. But gynaecologist advised not to take off the tooth because it is a very short time since delivery. Meanwhile she was suffered from spasm and stiffness in her jaw and neck muscles. Sometimes the pain spread into her whole body. Gynaecologist has provided her some antibiotics and pain killers. After 65 days of delivery, the the injured tooth was operated out (10 days before from now). After 3 days of the operation, gynaecologist advised to stop taking the tablets and said that the pain will be gradually decreased. But she felt severe pain in tooth and sometimes in head from the date of operation. She could not even take solid food. For the last two days, she again felt the stiffness in her neck and jaw muscles. Please advise us what should we do.