In an interview with the Daily Star, the singer said that she is impressed by the group's performance so far and feels confident that they will be able to expand their appeal.
She commented: "JLS are really representing. I think they'll do well in America - they could even be in the running for a Grammy."
Lewis cracked the US in 2008 with debut album Spirit and its lead single 'Bleeding Love'.
JLS are expected to launch their Stateside offensive in the spring, while R&B star Rihanna recently confirmed that she plans to record with them before the year is over.