Do anda think JKR refused to play Lily Potter in the first movie because she knew Lily would have a bigger role in the later films?

JKR stated in an interview that she was offered a role as Lily Potter in the first HP movie, where her only scenes would've been the brief flash of Lily and James' deaths and then the scene with the Mirror of Erised. She refused the role stating that she's not cut out to be an actress and would end up messing up somehow.
Do anda think that in reality she refused the role because she knew that Lily would later play a bigger part in the series and her actress might be required to participate in lebih demanding scenes?