Complex sentence: She has occasionally returned to the series since her departure, most notably, in character, at the age of 89,for a special programme dedicated to Emmerdale 5000th episode, where members of the cast were interviewed.
Split into simpler sentences: She has occasionally returned to the series since her departure. At the age of 89 she appeared in a special programme dedicated to Emmerdale 5000th episode, where members of the cast were interviewed.