Q: I lost my iPhone. I'm trying to use my friends' iPhone to track MY iPhone! Is this impossible, since we don't have my iPhone to install "Find Friends'"

My phone was stolen. I am trying to use my lady friend's iPhone to track my iPhone!

I've installed "Find My Friends" on lady friend's iPhone, then sent a request to allow tracking my iPhone. The request comes by email. I responded to the request but it appears that my stolen iPhone needs the app "Find My Friends" installed!! Is this the end of the line for tracking my stolen iPhone?!?! I need my iPhone pretty desperately!! :(