URGENT : How to confirm find my iphone was on my lost/stolen device

Hi,

I lost my iphone 4s. It was on IOS7. I signed into my icloud wepp app account went to find my iphone app and erased the iphone. But i am not sure find my iphone app on my lost device before was turned on or not. i just want to confirm if my find my iphone was not turned on, the icloud will still show my phone in device list or only if find my iphone was turned on it will show in my icloud (find my iphone apps). basically i want to know how to confirm find my iphone was turned on/off on my stolen device. its very important as i need to erase some imp data. kindly help