Has the company banked her cheque? Does she have acknowledgment of her cheque, resignation letter, and acceptance of her resignation?
She must have reported the work environment related issues to her company (bank).
Companies are expected to have a grievance redressal mechanism for employees and to be sensitive to work environment related issues involving female employees. It is believed that her issues were not addressed properly. It is not clear whether she reported the matter to the concerned employees in HR or grievance redressal staff, in writing or mentioned it as a reason in her resignation letter. She has all the reasons and rights to do so. She can still quote it. If she reported the matter in writing but did not receive any reply, it is serious default of company. She can demand to examine her personnel file. Her superiors/HR might have posted their (adverse) comments and that may be the reason for the studied silence/no response.
Company is under obligation to issue the service or work experience certificate. Company may sit on relieving certificate.
Hope she has submitted all company property under receipt and no issue is pending against her and she has secured another employment and enjoys good rapport in present company.
She can represent to the good office of her appointing authority, MD, Company Secretary, mentioning all incidents in chronological order and that despite all she has as per terms of her appointment letter submitted notice pay vide cheque number........dated..........drawn on bank.........for Rs........and has supplied the same on dated.........vide..........regd.post/courier/in person........on...., however company has till date not supplied her, despite her gentle representations, F&F, form 16,work experience certificate, PF withdrawal/transfer certificate, PF accumulation reports, NOC/NDC, relieving letter etc although company is duty bound to supply in reasonable time of 30 days. Since the concerned offices and officials did not execute their responsibility, she has submitted her gentle representations to the highest and good office of Chairman on dated.........and no reply to her representation has been supplied to her till date. She can ask the good offices to intervene and respond to her within say 15 days in writing by registered post or she shall be at liberty to take up the matter with appropriate forums (which can be social and legal forums, ministries and minister, NGO's, print and electronic media, women cell, courts of law etc at their cost and consequences).
This should help.
Other options can be legal notice, complaint with local office of the labor commissioner.