In September 2009, Ewen joined the group Sugababes as the replacement for Keisha Buchanan.
Since September 2009, Ewen is a member of the girl group Sugababes.
Since September 2009, Ewen is a member of the girl group Sugababes.
Rewrite the sentence to be simpler: In September 2009, Ewen joined the group Sugababes as the replacement for Keisha Buchanan. Output: