Complex sentence: At age 11, on October 2012, she climbed "Southern Smoke" at the Red River Gorge, a grade 5.14c (8c +) sport climb, becoming the youngest person to climb a route of this difficulty.
Split into simpler sentences: At age 11 in October 2012, she climbed Southern Smoke at the Red River Gorge, a grade 5.14c (8c +) sport climb. Ashima is the youngest person to climb a route of this difficulty.