Complex sentence: She was armed with 12 guns, ranging in size from 8-pounders to 18-pounders and had a crew of 57 men, of whom one was killed and two were wounded.
Split into simpler sentences: She was armed with 12 guns, ranging in size from 8-pounders to 18-pounders. Her crew numbered 57 men, of whom one was killed and two were wounded.