Having flown throuhg Frankfurt a few times, Uchenna and Joyce's took a HUGE risk with that hour connection. The Frankfurt airport is huge and often times for international flights the terminal you arrive and leave in are on opposite sides of the airport. Plus you have to go through security lines a couple of times which also includes the passport authorities.
If they had not been in economy and maybe in business class or first class it may not have been a problem though. My last flight through Frankfurt was on my way back from Berlin last May and my flight was late. Fortunately for me, I was on a business trip and flying in business class so when I stepped out of the gate in Frankfurt, there was an employee of Lufthansa waiting for me to escort me to through the aiport. She actually put me on a shuttle on the tarmac, drove me across the airport and walked me passed the line at the passport control gate and through to the next security line to have my carry on x-rayed and then I was on to my gate to board the plane. That was my saving grace on that trip.