"This story - I'm more excited about it than Molly is," she said.
"I'm like: 'If this is true I want to meet Kate... she's up there!'"
Twenty-four-year-old Mollie was introduced to Harry in July 2010, at a polo match in Surrey's Hurtwood club.
She's been single since February, when she split from model David Gandy, after work commitments drove them apart.
Harry, whose long-term realtionship with Chelsy Davy ended in 2009, was linked with the pretty singer after it was said they enjoyed a private kareoke session with frineds at london's Bunga Bunga club.