What are the ways to proof employment of wife in divorce case

My divorce case is registered in madhyapradesh district court, I got married on 2009 and got saperated in 2011 She delivered a baby girl in 2011 itself Summary of case She left me without any base reason After 2 months I tried to take her back, which she refused and signed a 500rs stamp paper with all details written for divorce in presence of a advocate in her home only After 4 months I filled for the divorce case in family court under cruelty (because that 500rs stamp paper is not enough for proper divorce, though that is very useful till now) 2011 she delivered a baby girl and asked for money , currently I am giving 4000rs per month since june 2012. She went for her higher studies, and working here and there since Now I got to know about her current employer, its a private hospital in pune I called up the hospital and asked for her name, receptionist answered and confirm that she is working here. However phone call is not sufficient I talked with one detective agency they said they cant get salary slip(as its illegal) but they can record some videos/audio to get the employment proof. Also i can not pay 30000 , 40000 to detective agency :( How can i get her employment detail proof? What is a besy way to get this? Is there any way I can ask directly to that hospital? What if she left job after she got to know that I knew where she is working?