Tal Wilkenfeld. She was like 21 when they played Crossroads.
I was also amazed, and immediately jumped on google. She started playing guitar at 14, switched to bass at 17 so she's obviously gifted. The Jeff Beck performance is great, especially because of her interplay with Jeff, and that performance alone is worth the cost of the video.
and smokin' hot. Probably no one will believe me but the dvd seems to have been digitally "de-enhanced". As anyone who was there will know it apparently was very cold on stage : ) and the effects are not to be seen on the dvd. Even my female cousin commented on this. That show however and performance in particular were amazing!