I think she would have died as well. She was strong but not as resourceul as Buffy. Just think at when she first arrives in Sunnydale, she was running from that vampire, can't remember the name, who had killed her Watcher and she was very afraid and looking for Buffy's help. And she was older and more trained than Buffy! No way she would have survived the Cruciamentum imo

And yes, it would have been interesting to see others Slayers go through the test!