What Happened to the Words Frail and Frail?

Consider words like frail and fragile. Ultimately, there are both variations of the same latin root word, fragilus. In that particular case, the two words were considered to be distinct words within english. And frale never got a new letter g within english. It continued to be spelled like it sounded. The same thing happened with the words secure and sure. They're both derived from the latin word secures. But again, secure and sure were apparently considered to beinct enough that shure was left alone.