Kortney Olson is a bodybuilder and athlete born in the USA who's now living in Australia. She became Australia's first ever female arm wrestling champion in 2012. As you can see, she is extremely strong and fit, especially her thighs are. She crushes watermelons like it's nothing.
There is another girl who's capable to do the same thing. Her name is Olga Liaschuk from Kiev, Ukraine. She is 30 years old and is the Guinness world record holder for breaking the fruit with her legs. She managed to crush three watermelons in just 14 seconds on live TV.