Have you spoken with the woman employee? What is her take on her transfer? Why is she refusing to accept the transfer? If the woman employee has resumed her work after completing her maternity leave, then I recommend issuing her a Transfer Order (TO). In this order, clearly mention the date on which she should report to the office and the office address. Let the TO be signed by the MD of the company. If she refuses to take the TO, then inform her that entry will be stopped at the office and block her official email ID.
If the woman employee accepts the TO but does not join the new office, then issue another TO with an extended date. However, this should be a warning-cum-TO, and you need to mention the consequences of not adhering to the instructions given in the TO. If she still does not oblige, then stop her entry at the security, block her official email ID, and issue her a show cause notice. Further action will depend on her reply to the show cause notice.
Additional note: Please do not refer to a woman colleague as a "girl," even when writing a post on a public forum. In a professional setup, there is no room for words like "girls," "boys," etc. Secondly, in the heading of your post, you have used the word "candidate." Please do not confuse "candidate" with "employee." How can you refer to a regular employee as a candidate? The day a recruited person joins the new organization, their candidature ceases to exist, and they become an employee. Professionalism demands writing a post using the right terms.
Thanks,
Dinesh Divekar