Complex sentence: She operated alone throughout the "Mountwood" and "Woodchurch" refurbishment, her last full season was 1989, in 1991 she was used until the two sisters returned in time for the QE2's first visit to Liverpool.
Split into simpler sentences: She operated alone throughout the "Mountwood" and "Woodchurch" refurbishment, her last full season was 1989. In 1991, she was used until the two sisters returned in time for the QE2's first visit to Liverpool.