Forgery

Last year my sister in law was working in Delhi as a patient care to one elderly couple 24 hours.They were very nice to her but once she wanted leave but they did not give, so she left the house without telling them.After some time elderly couple filed FIR telling that she took gold and valuable things and ran away.police called my sister in law and questioned her about this matter in front of elderly couple for 3 to 4 days regularly.even they went to see the place where she was staying but found nothing.my sister in law also knew the children of elderly couple and had gone to them and according to them their parents just want to put my sister in law in trouble so she can work with them for long time but they never turn to police in support of my sister in law in spite of assurance that they will support.Now after 1 year 3 months police has sent 1 letter to my hometown police station in Jharkhand to find out where she is and weather she has been arrested earlier,either her address is changed or not and asked to send Delhi by my home town Police station.Here i wanted to know weather my sister in law may be arrested or what action police may take against her or any problem may come for my sister in law.Please advise what can we do.