Nikola Tesla, the prolific Serbian-American inventor and radio pioneer, filed a U.S. patent, granted on March 17, 1903 which doesn’t mention the phrase “frequency hopping” directly, but certainly alludes to it. Entitled “Method of Signaling,” the patent describes a system that would enable radio communication “without any danger of the signals or messages begin disturbed, intercepted, interfered with in any way”.
Tesla’s patent details a system whereby transmitter and receiver are synchronized and hop between two channels (although the patent notes any number of channels could be used) by altering the carrier frequency in a predetermined sequence to avoid interference.
So, although she did receive a patent for the "implementation" of a device that used frequency hopping, she was not the inventor of frequency hopping. It was mentioned by several people from the early 1900s through the 1930s.
But to be clear I do believe that she was a very classy lady and that she and her composer were very clever to come up this this implementation of frequency hopping, although IIRC the military rejected its implementation.