Complex sentence: In it Miss Willard portrayed the character of Salvation Army worker, Priscilla Worth, which turned out to be not only her final performance for 1966, but also the final acting role of her career.
Split into simpler sentences: In it Miss Willard portrayed the character of Salvation Army worker, Priscilla Worth. The casting turned out to be not only her final appearance for 1966, but also the final acting role of her career.