Bro Style.whist, long time no see any of your post or threads. Anyway relating to your query, i'm afraid your lady in waiting might have really gone for a detour like what boss had mentioned i.e. she is now currently uncontactable because she has decided to overstay i.e jump aeroplane. No doubt, all the bros here are making speculations on your behalf.. but this seems to be the most likely case and scenario right now
Well u can still try making enquiries with ICA and see whether they are able to assist and address your issue in any way. If you make a police report, she will be considered as a missing person. And if, I mean if she ever gets caught or should I say found by the police, then she will certainly serve her dues in the cell before being repatriated upon release. Hope this helps