Complex sentence: When she was 14, she taught 30 pupils of her own, and two years later she became a piano professor, under Myra Hess at Tobias Matthay's famed London music school.
Split into simpler sentences: When she was 14, she taught 30 pupils of her own. At 16 she became a piano professor, under Pianist Myra Hess at Tobias Matthay's famed London music school.