Complex sentence: Betty was the third of six children born to devout Roman Catholic parents, Marita and Frank Bisceglia, an Irish-American mother and an Italian father who had founded a plastering firm with his brothers.
Split into simpler sentences: Betty was the third of six children born to devout Roman Catholic parents, Marita and Frank Bisceglia. Her mother was Irish-American and her father was of Italian descent; he founded a plastering firm with his brothers.