Complex sentence: When she joined the Ursulines, a Roman Catholic religious institute in 1960, she took the name Sister Laurentine, in honor of an Ursuline martyred during the French Revolution.
Split into simpler sentences: When she joined the Ursulines, a Roman Catholic religious institute. In 1960, she took the name Sister Laurentine, in honor of an Ursuline martyred during the French Revolution.