Resignation Period Notice

Dear Sir, It is an honor to write to you. I need your kind guidance on the captioned issue. My fiance is currently working in an MNC ( Private Company) since 1 and half year. There is no bond to the job and normal notice is 2 Months. Owing to sudden medical emergency at home she has to resign from her current job on 1st December. She has resigned formally via email notification to management and has mentioned that she would be able to serve till 15th December and also mentioned that she is OK to pay remaining notice period in lieu of money if required as per company policy. Please find herein the clause as per offer letter towards her separation from service. I would need your kind guidance on 1. Can the employer force someone to work ? 2.she has informed 15 days prior still organisation has not relieved her from The job . 3.Owing to this mental pressure she is even under doctor consultation, despite of which still organisation is not allowing her to go rather asking her she can abscond but no relieving can be given 4.Kindly guide as per labour law if an employee wishes to resign can the organisation stop her. Also note the employee is a very dedicated employee and till DATe no negative case is against the employee. Please note in the offer letter given to the candidate it says under extreme situation based on discretion of management notice can be reduced or waived.