Two Finger Style question

In the following video it doesn't look like she's doing one of the standard two finger style patterns. Is this a pattern she came up with or is it a standard bluegrass or guitar picking pattern?

http://www.youtube.com/watch?v=dbXLjouRB1Q

Great band by the way. I chose that video because it's easy to see but check out these two more professional ones:

http://www.youtube.com/watch?v=twrYh8tPcCg

http://www.youtube.com/watch?v=X_nZJOSrf8Q

She's alternating between strumming and that two finger style in those ones. 

Thanks.