Complex sentence: Amelia Shepherd is the youngest sister of Dr. Derek Shepherd, and like her brother, she is also an excellent neurosurgeon whose ambition in proving herself equal to her brother is only surpassed by her surgical skill.
Split into simpler sentences: Amelia Shepherd is the youngest sister of Dr. Derek Shepherd, and like her brother, she is also an excellent neurosurgeon. Her ambition to prove herself equal to her brother is only surpassed by her surgical skill.