Simplify the following text for a Grade 11 native English-speaking person.
Original: However , while filming the original pilot `` Serenity '' , Whedon decided that Rebecca Gayheart was unsuitable for the role of Inara Serra , and shot her scenes in singles so that it would be easier to replace her .
Simplified: However , while filming the original pilot `` Serenity '' , Whedon saw that the actress cast as Inara Serra ( Rebecca Gayheart ) was not right for the role .