The Lovell Sisters Band performed on the Millennium Stage at the Kennedy Center on August 11, 2007 and that show is now available for online viewing.
The audio mix is a little disappointing during the first part of the show. This is not the fault of the girls though and it does improve marginally as the concert proceeds. Thankfully the vocals are mixed up where you can hear them most of the time, but the mandolin is often absent just when you want to hear Rebecca cut loose. None the less, this band is worth hearing, even with a less than desirable audio mix.
Check their tour schedule to see them near you.