The Smile hitmaker sparked a feud with Cole in 2006 by attacking her in a song, and she reignited the row in 2012 by referencing her rival's assault conviction from 2003 in a post on Twitter.com.
However, Allen now admits the fight was pointless and she has outed herself as a fan of the singer, whose solo career was boosted by a judging role on Britain's The X Factor.
Allen tells Q magazine, "I wish the whole Cheryl Cole thing hadn't happened. I like her. She's good on X Factor, she's pretty, she's got balls. I like women who do well."